Nucleic Acids Research, 2004, Vol. 32, Database issue D303-D306
© 2004 Oxford University Press
RegulonDB (version 4.0): transcriptional regulation, operon organization and growth conditions in Escherichia coli K-12
Program of Computational Genomics, CIFN, UNAM. A.P. 565-A Cuernavaca, Morelos 62100, Mexico
*To whom correspondence should be addressed. Tel: +527 77 313 2063; Fax +527 77 317 5581; Email: ecoli-t1{at}cifn.unam.mx
The authors wish it to be known that, in theirr opinion, the first five auhtors should be regarded as joint First Authors
Received September 12, 2003; Revised October 8, 2003; Accepted October 29, 2003
| ABSTRACT |
|---|
|
|
|---|
RegulonDB is the primary database of the major international maintained curation of original literature with experimental knowledge about the elements and interactions of the network of transcriptional regulation in Escherichia coli K-12. This includes mechanistic information about operon organization and their decomposition into transcription units (TUs), promoters and their
type, binding sites of specific transcriptional regulators (TRs), their organization into regulatory phrases, active and inactive conformations of TRs, as well as terminators and ribosome binding sites. The database is complemented with clearly marked computational predictions of TUs, promoters and binding sites of TRs. The current version has been expanded to include information beyond specific mechanisms aimed at gathering different growth conditions and the associated induced and/or repressed genes. RegulonDB is now linked with Swiss-Prot, with microarray databases, and with a suite of programs to analyze and visualize microarray experiments. We provide a summary of the biological knowledge contained in RegulonDB and describe the major changes in the design of the database. RegulonDB can be accessed on the web at the URL: http://www.cifn.unam.mx/Computational_Biology/regulondb/. | INTRODUCTION |
|---|
|
|
|---|
Escherichia coli has been a model organism since the beginning of molecular biology. Current post-genomic research in bioinformatics, network analyses and modeling, and system biology, can strongly benefit from studies in E.coli, given the large amount of accumulated knowledge of the molecular biology of this cell. It may be that this is the cell for which we know more about the function of its genes, its metabolism and transcriptional regulation. This knowledge is the foundation for the proposal within the International E.coli Alliance, to achieve in E.coli, as a long-term goal, the first whole-cell model (1). We contribute to this international effort with RegulonDB, the primary database of the major international maintained curation of original literature with experimental knowledge about the elements and interactions of the network of transcriptional regulation in E.coli K-12. It is a relational database containing mechanistic information about operon organization and their decomposition in transcription units (TUs), promoters and their
type, binding sites of specific transcriptional regulators (TRs), their organization into regulatory phrases, active and inactive conformations of TRs, as well as terminators and ribosome binding sites. All this information is mapped onto the E.coli K12 chromosome. The database is updated constantly by searching in original publications, and is complemented by computational predictions. Every object has experimental evidence, and a direct link to the original publication via MedLine. Previous publications explain the initial relational design and subsequent modifications (25).
We estimate that we have
2025% of all predicted interactions of the network (see the summary of the increasing content of RegulonDB by year shown in Table 1). RegulonDB has been used in different types of analyses by the scientific community, such as predictions of regulatory sites (6) and operons (710); complementation of other databases, specifically, the mechanistic information gathered from the literature is included in EcoCyc (11); reconstruction of metabolic pathways with regulatory information (12); analyses of the connectivity and over-represented motifs in the regulatory network of E.coli (1314); studies identifying objective criteria that characterize and define global regulators in E.coli (15); studies on the evolution of regulatory mechanisms (1617), as well as analyses of microarray experiments (18).
|
The motivation to incorporate additional information comes from the fact that experimental research in E.coli, as in any other organism, goes well beyond knowledge about the molecular biology involved in regulation and transcription. Physiological and genetic studies add a rich layer of knowledge about the internal structure of the cell. There is, for instance, a large number of publications describing the effect in the expression of specific genes when changing the growth conditions of the cell, specifically experiments studying the effects of deletions of regulatory genes. This genetic and physiological information provides knowledge without necessarily specifying the corresponding molecular mechanisms.
Having this information expands the utility of RegulonDB. For instance, it can be used to compare and validate microarray experiments (18). Computational genomics has grown in methods and goals, moving from a sequence-centered approach to one where regulatory networks and interactions have become the main focus. Understanding the regulatory network will be crucial in the future goal of modeling, in silico, the behavior of E.coli as an entire cell (1).
In the following, we describe how growth conditions are modeled in the databases and then summarize the computational changes and additions to the database.
| RESULTS |
|---|
|
|
|---|
Gene expression changes as a function of growth conditions in RegulonDB
Free-living bacteria have to maintain a constant monitoring of extracellular physicochemical conditions in order to respond and modify their gene expression patterns accordingly. A series of genes whose products are involved in sensing and incorporating the different nutritional elements, as well as products sensing the concentration of toxic elements, are present in E.coli. These sensing systems are connected through metabolic intermediates to the transcriptional machinery, which in turn modifies the expression of genes whose products are involved in the response and adaptation to the corresponding changes in the environment. For the past 2 years, we have been collecting and organizing, from the original literature, information about different growth conditions and the associated observed effects in the transcription of E.coli genes. Since the first published version of RegulonDB (2), we described in the relational design the modeling of physiological conditions and their connection to the transcriptional machinery. However, as mentioned in that paper, we were not then involved in gathering such types of information.
After an analysis of several different conditions and systems involved, we decided to implement a model where the following properties and descriptions are considered essential: (i) a general or global condition; (ii) the control condition; (iii) the specific experimental condition; (iv) the growth media used; (v) the genes affected; and (vi) the effect of the experimental condition in the expression of the affected genes (induced, repressed or no effect). Since every added object in RegulonDB is supported by associated evidence and literature citation, we had to implement a set of criteria to classify the evidence concerning different levels of expression of genes.
To quantify gene expression, by far the most frequent methodology is that of transcriptional fusion. These studies provide quantitative information easy to classify. We incorporate as affected genes those with an expression change of least a 2-fold increase or decrease. Otherwise, genes are added to the database considered cautiously as genes with no effect or no change in expression under the specified condition. In a small fraction of cases there is no quantitative information on the level of expression of the affected gene and, therefore, its classification is not straightforward. In those cases the curators criterion is essential. The classification of the level of expression depends on the authors statements, the visual inspection of the spots in the figures in the publication, as well as, ideally, additional evidence in other publications.
Whenever available, additional information is incorporated, i.e. mechanistic properties that are already part of RegulonDB: (i) the transcription unit to which the gene belongs, the associated promoter and terminator; (ii) the regulatory protein that is involved; (iii) the set of sites in the DNA involved in regulation of transcription; (iv) the allosteric conformations and associated effectors involved; as well as (v) the intermediate metabolites or proteins that participate in the regulatory sensing mechanism. The design and discussion of the potential applications of this corpus of knowledge is presented in more detail in a separate paper (19).
Table 2 summarizes the information that we have gathered up to September 2, 2003 concerning physiological conditions and their effect on the transcription of genes. The numbers in this table account for unique cases, thus 327 genes have information about their expression in 83 different conditions. Since there is information for genes affected in different conditions, these genes are described a total of 679 times with their associated specific conditions.
|
Computational changes to the interface
We have changed the web interface so that the main menu remains fixed throughout navigation. For instance, the ZoomTool that displays the whole genome is now shown without invoking an additional external window. We have added a new selection by functional class within the graphic display. A very useful navigation feature in the analyses of transcriptome data is the new capability of taking a file with a list of genes and getting their display in the circular genome. GETools, a suite of programs linked to the database, was specifically designed to analyze, generate graphic displays and extract information from RegulonDB, from an input based on microarray files (20).
Alignments and matrices for each transcriptional regulator have been updated, and their automatic update as new sites from the literature accumulation has been implemented. The process begins by getting all the regulatory binding sites with experimental evidence, then, the program CONSENSUS 5c (21) is applied to generate the corresponding weight matrix. We get the first matrix of the second cycle, where all the sequences are included. This matrix and the program PATSER 3b (22) are used to score these same known sites. From this scoring, we define alternative thresholds available for the user, to search for similar sites in other DNA sequences. RegulonDB users can obtain these data by querying for Transcriptional Regulator.
There are two ways the user can access the information on growth conditions that affect specific genes, either through a list of conditions available in the main page, or by searching for individual genes. Furthermore, we have added links to the OU microarray database (http://www.ou.edu/microarray/Macroarray/). RegulonDB is also now linked to Swiss-Prot and Swiss-Prot has links to RegulonDB.
| DISCUSSION |
|---|
|
|
|---|
The information on the effect of growth conditions on gene expression will be of great value in defining and modeling functional modules in cellular physiology. Metabolic intermediates and environmental signals, functioning as allosteric effectors of transcriptional factors, are additionally available in RegulonDB. Together, this information will enable a more complete description of sets, or modules, of genes as they are expressed in E.coli in response to different environmental conditions.
An example of the use of the knowledge gathered in the database is the comparison of what RegulonDB would predict in terms of expression profiles, and what is observed in microarray experiments (19).
We have also made a proposal of diagnostic criteria to identify global regulators, where we have shown that global regulators are active in a larger number of different growth conditions than specific or dedicated regulators. This observation enriches the original requirement of global regulators to regulate genes that belong to different metabolic pathways (15).
The current expansion of data gathered and organized in RegulonDB will reinforce and contribute to the efforts of the international community in the long-term goal of modeling of the full E.coli cell (1).
We kindly ask users of RegulonDB to cite this article.
| ACKNOWLEDGEMENTS |
|---|
We acknowledge Rosa María Gutiérrez-Ríos and Mónica Peñaloza-Spínola their participation in discussions on growth conditions, and Víctor del Moral and Romualdo Zayas for their computer support. This work was supported by NIH grants GM62205-02 and 1-R01-RR07861.
| REFERENCES |
|---|
|
|
|---|
- Holden,C. (2002) Alliance launched to model E. coli. Science, 297, 14591460.
- Huerta,A.M., Salgado,H., Thieffry,D. and Collado-Vides,J. (1998) RegulonDB: a database on transcription regulation in Escherichia coli. Nucleic Acids Res., 26, 5560.
[Abstract/Free Full Text] - Salgado,H., Santos,A., Garza-Ramos,U., van Helden,J., Díaz,E. and Collado-Vides,J. (1999) RegulonDB (version 2.0): a database on transcriptional regulation in Escherichia coli. Nucleic Acids Res., 27, 5960.
[Abstract/Free Full Text] - Salgado,H., Santos-Zavaleta,A., Gama-Castro,S., Millán-Zárate,D., Blattner,F.R. and Collado-Vides,J. (2000) RegulonDB (version 3.0): transcriptional regulation and operon organization in Escherichia coli. Nucleic Acids Res., 28, 6567.
[Abstract/Free Full Text] - Salgado,H., Santos-Zavaleta,A., Gama-Castro,S., Millán-Zárate,D., Díaz-Peredo,E., Sánchez-Solano,F., Pérez-Rueda,E., Bonavides-Martínez,C. and Collado-Vides,J. (2001) RegulonDB (version 3.2): Transcriptional regulation and operon organization in Escherichia coli K-12. Nucleic Acids Res., 29, 7274.
[Abstract/Free Full Text] - Tan,K., Moreno-Hagelsieb,G., Collado-Vides,J. and Stormo,G.D. (2001) A comparative genomics approach to prediction of new members of regulons. Genome Res., 11, 566584.
[Abstract/Free Full Text] - Ermolaeva,M.D., White,O. and Salzberg,S.L. (2001) Prediction of operons in microbial genomes. Nucleic Acids Res., 29, 12161221.
[Abstract/Free Full Text] - Salgado,H., Moreno-Hagelsieb,G., Smith,T.F. and Collado-Vides,J. (2000) Operons in Escherichia coli: Genomic analyses and predictions. Proc. Natl Acad. Sci. USA, 97, 66526657.
[Abstract/Free Full Text] - Moreno-Hagelsieb,G. and Collado-Vides,J. (2002) Operon conservation from the point of view of Escherichia coli and inference of functional interdependence of gene products from genome context. In Silico Biol., 2, 8795.[Medline]
- Zheng,Y., Szustakowski,J.D., Fortnow,L., Roberts,R.J. and Kasif,S. (2002) Computational identification of operons in microbial genomes. Genome Res., 12, 12211230.
[Abstract/Free Full Text] - Karp,P.D., Riley,M., Saier,M., Paulsen,I.T., Collado-Vides,J., Paley,S.M., Pellegrini-Toole,A., Bonavides,C. and Gama-Castro,S. (2002) The EcoCyc Database. Nucleic Acids Res., 30, 5658.
[Abstract/Free Full Text] - Covert,M.W., Schilling,C.H. and Palsson,B. (2001) Regulation of gene expression in flux balance models of metabolism. J. Theor. Biol., 213, 7388.[CrossRef][ISI][Medline]
- Oosawa,C. and Savageau,M.A. (2002) Effects of alternative connectivity on behavior of randomly constructed Boolean networks. Physica D., 170, 143161.[CrossRef]
- Shen-Orr,S.S., Milo,R., Mangan,S. and Alon,U. (2002) Network motifs in the transcriptional regulation network of Escherichia coli. Nature Genet., 31, 6468.[CrossRef][ISI][Medline]
- Martínez-Antonio,A. and Collado-Vides,J. (2003) Identifying global regulators in transcriptional regulatory networks in bacteria. Curr. Opin. Microbiol., 6, 482489.[CrossRef][ISI][Medline]
- Pérez-Rueda,E. and Collado-Vides,J. (2000) The repertoire of DNA-binding transcriptional regulators in Escherichia coli. Nucleic Acids Res., 28, 18381847.
[Abstract/Free Full Text] - Babu,M.M. and Teichmann,S.A. (2003) Evolution of transcription factors and the gene regulatory network in Escherichia coli. Nucleic Acids Res., 31, 12341244.
[Abstract/Free Full Text] - Gutiérrez-Ríos,R.M., Rosenblueth,D.A., Loza,J.A., Huerta,A., Glasner,J.D., Blattner,F. and Collado-Vides,J. (2003) Regulatory network of Escherichia coli: Consistency between literature knowledge and microarray profiles. Genome Res., 13, 24352443.
[Abstract/Free Full Text] - Martínez-Antonio,A., Salgado,H., Gama-Castro,S., Gutiérrez-Ríos,R.M., Jiménez-Jacinto,V. and Collado-Vides,J. (2003) Environmental conditions and transcriptional regulation in Escherichia coli: A physiological integrative approach. Biotechnol. Bioeng., 84, 743749.
- Huerta,A.M., Glasner,J.D., Jin,H., Blattner,F.D., Gutiérrez-Ríos,R.M. and Collado-Vides,J. (2002) GETools: Gene Expression Tool for analysis of transcriptome experiments in Escherichia coli. Trends Genet., 18, 217218.[CrossRef][Medline]
- Stormo,G.D. and Hartzell,G.W.,3rd (1989) Identifying protein-binding sites from unaligned DNA fragments. Proc. Natl Acad. Sci. USA, 86, 11831187.
[Abstract/Free Full Text] - Hertz,G.Z., Hartzell,G.W.,3rd and Stormo,G.D. (1990). Identification of consensus patterns in unaligned DNA sequences known to be functionally related. Comput. Appl. Biosci., 6, 8192.
[Abstract/Free Full Text]
This article has been cited by other articles:
![]() |
L. R. Jarboe, D. R. Hyduke, L. M. Tran, K. J. Y. Chou, and J. C. Liao Determination of the Escherichia coli S-Nitrosoglutathione Response Network Using Integrated Biochemical and Systems Analysis J. Biol. Chem., February 22, 2008; 283(8): 5148 - 5157. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. R. Hyduke, L. R. Jarboe, L. M. Tran, K. J. Y. Chou, and J. C. Liao Integrated network analysis identifies nitric oxide response networks and dihydroxyacid dehydratase as a crucial target in Escherichia coli PNAS, May 15, 2007; 104(20): 8484 - 8489. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. H. Bergman, K. D. Passalacqua, P. C. Hanna, and Z. S. Qin Operon Prediction for Sequenced Bacterial Genomes without Experimental Information Appl. Envir. Microbiol., February 1, 2007; 73(3): 846 - 854. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Dam, V. Olman, K. Harris, Z. Su, and Y. Xu Operon prediction using both genome-specific and general genomic information Nucleic Acids Res., January 12, 2007; 35(1): 288 - 298. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Reed, T. R. Patel, K. H. Chen, A. R. Joyce, M. K. Applebee, C. D. Herring, O. T. Bui, E. M. Knight, S. S. Fong, and B. O. Palsson Systems approach to refining genome annotation PNAS, November 14, 2006; 103(46): 17480 - 17484. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Shen, X. Feng, Y. Yuan, X. Luo, T. P. Hatch, K. T. Hughes, J. S. Liu, and Y.-x. Zhang Selective Promoter Recognition by Chlamydial {sigma}28 Holoenzyme J. Bacteriol., November 1, 2006; 188(21): 7364 - 7377. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. P. Brynildsen, L. M. Tran, and J. C. Liao Versatility and Connectivity Efficiency of Bipartite Transcription Networks Biophys. J., October 15, 2006; 91(8): 2749 - 2759. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Yu and M. Gerstein Colloquium Papers: Genomic analysis of the hierarchical structure of regulatory networks PNAS, October 3, 2006; 103(40): 14724 - 14731. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Pelosi, L. Kuhn, D. Guetta, J. Garin, J. Geiselmann, R. E. Lenski, and D. Schneider Parallel Changes in Global Protein Profiles During Long-Term Experimental Evolution in Escherichia coli Genetics, August 1, 2006; 173(4): 1851 - 1869. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. GuhaThakurta Computational identification of transcriptional regulatory elements in DNA sequence Nucleic Acids Res., July 19, 2006; 34(12): 3585 - 3598. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Lozada-Chavez, S. C. Janga, and J. Collado-Vides Bacterial regulatory networks are extremely flexible in evolution Nucleic Acids Res., July 13, 2006; 34(12): 3434 - 3445. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G. Franchini and T. Egli Global gene expression in Escherichia coli K-12 during short-term and long-term adaptation to glucose-limited continuous culture conditions Microbiology, July 1, 2006; 152(7): 2111 - 2127. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Rawal, V. B. R. Kummarasetti, J. Ravindran, N. Kumar, K. Halder, R. Sharma, M. Mukerji, S. K. Das, and S. Chowdhury Genome-wide prediction of G4 DNA as regulatory motifs: Role in Escherichia coli global regulation. Genome Res., May 1, 2006; 16(5): 644 - 655. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. L. Grigorova, N. J. Phleger, V. K. Mutalik, and C. A. Gross Insights into transcriptional regulation and {sigma} competition from an equilibrium model of RNA polymerase binding to DNA PNAS, April 4, 2006; 103(14): 5332 - 5337. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Riley, T. Abe, M. B. Arnaud, M. K.B. Berlyn, F. R. Blattner, R. R. Chaudhuri, J. D. Glasner, T. Horiuchi, I. M. Keseler, T. Kosuge, et al. Escherichia coli K-12: a cooperatively developed annotation snapshot--2005 Nucleic Acids Res., January 5, 2006; 34(1): 1 - 9. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. K. Kummerfeld and S. A. Teichmann DBD: a transcription factor prediction database Nucleic Acids Res., January 1, 2006; 34(suppl_1): D74 - D81. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. L. Jensen, M. P. Styczynski, I. Rigoutsos, and G. N. Stephanopoulos A generic motif discovery algorithm for sequential data Bioinformatics, January 1, 2006; 22(1): 21 - 28. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Okuda, T. Katayama, S. Kawashima, S. Goto, and M. Kanehisa ODB: a database of operons accumulating known operons across multiple genomes Nucleic Acids Res., January 1, 2006; 34(suppl_1): D358 - D362. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Salgado, S. Gama-Castro, M. Peralta-Gil, E. Diaz-Peredo, F. Sanchez-Solano, A. Santos-Zavaleta, I. Martinez-Flores, V. Jimenez-Jacinto, C. Bonavides-Martinez, J. Segura-Salazar, et al. RegulonDB (version 5.0): Escherichia coli K-12 transcriptional regulatory network, operon organization, and growth conditions Nucleic Acids Res., January 1, 2006; 34(suppl_1): D394 - D397. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Boyer, A. Morgat, L. Labarre, J. Pothier, and A. Viari Syntons, metabolons and interactons: an exact graph-theoretical approach for exploring neighbourhood between genomic and functional data Bioinformatics, December 1, 2005; 21(23): 4209 - 4215. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Zwir, H. Huang, and E. A. Groisman Analysis of differentially-regulated genes within a regulatory network by GPS genome navigation Bioinformatics, November 15, 2005; 21(22): 4073 - 4083. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Fang, E. Rocha, and A. Danchin How Essential Are Nonessential Genes? Mol. Biol. Evol., November 1, 2005; 22(11): 2147 - 2156. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. V. Morozov, J. J. Havranek, D. Baker, and E. D. Siggia Protein-DNA binding specificity predictions with structural models Nucleic Acids Res., October 24, 2005; 33(18): 5781 - 5798. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Hu, B. Li, and D. Kihara Limitations and potentials of current motif discovery algorithms Nucleic Acids Res., September 2, 2005; 33(15): 4899 - 4913. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. D. Herring, M. Raffaelle, T. E. Allen, E. I. Kanin, R. Landick, A. Z. Ansari, and B. O. Palsson Immobilization of Escherichia coli RNA Polymerase and Location of Binding Sites by Use of Chromatin Immunoprecipitation and Microarrays J. Bacteriol., September 1, 2005; 187(17): 6166 - 6174. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. N. Vemuri and A. A. Aristidou Metabolic Engineering in the -omics Era: Elucidating and Modulating Regulatory Networks Microbiol. Mol. Biol. Rev., June 1, 2005; 69(2): 197 - 216. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Pasek, A. Bergeron, J.-L. Risler, A. Louis, E. Ollivier, and M. Raffinot Identification of genomic features using microsyntenies of domains: Domain teams Genome Res., June 1, 2005; 15(6): 867 - 874. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Balazsi, A.-L. Barabasi, and Z. N. Oltvai Topological units of environmental signal processing in the transcriptional regulatory network of Escherichia coli PNAS, May 31, 2005; 102(22): 7841 - 7846. [Abstract] [Full Text] [PDF] |
||||
![]() |
P.-E. Jacques, A. L. Gervais, M. Cantin, J.-F. Lucier, G. Dallaire, G. Drouin, L. Gaudreau, J. Goulet, and R. Brzezinski MtbRegList, a database dedicated to the analysis of transcriptional regulation in Mycobacterium tuberculosis Bioinformatics, May 15, 2005; 21(10): 2563 - 2565. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Zhao, M. Liu, and R. R. Burgess The Global Transcriptional Response of Escherichia coli to Induced {sigma}32 Protein Involves {sigma}32 Regulon Activation Followed by Inactivation and Degradation of {sigma}32 in Vivo J. Biol. Chem., May 6, 2005; 280(18): 17758 - 17768. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Balazsi and Z. N. Oltvai Sensing Your Surroundings: How Transcription-Regulatory Networks of the Cell Discern Environmental Signals Sci. Signal., May 3, 2005; 2005(282): pe20 - pe20. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. Janga, J. Collado-Vides, and G. Moreno-Hagelsieb Nebulon: a system for the inference of functional relationships of gene products from the rearrangement of predicted operons Nucleic Acids Res., May 2, 2005; 33(8): 2521 - 2530. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Liu, T. Durfee, J. E. Cabrera, K. Zhao, D. J. Jin, and F. R. Blattner Global Transcriptional Programs Reveal a Carbon Source Foraging Strategy by Escherichia coli J. Biol. Chem., April 22, 2005; 280(16): 15921 - 15927. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Salmon, S.-p. Hung, N. R. Steffen, R. Krupp, P. Baldi, G. W. Hatfield, and R. P. Gunsalus Global Gene Expression Profiling in Escherichia coli K12: EFFECTS OF OXYGEN AVAILABILITY AND ArcA J. Biol. Chem., April 15, 2005; 280(15): 15084 - 15096. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. P. Westover, J. D. Buhler, J. L. Sonnenburg, and J. I. Gordon Operon prediction without a training set Bioinformatics, April 1, 2005; 21(7): 880 - 888. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Adams and Z. Jia Structural and Biochemical Evidence for an Enzymatic Quinone Redox Cycle in Escherichia coli: IDENTIFICATION OF A NOVEL QUINOL MONOOXYGENASE J. Biol. Chem., March 4, 2005; 280(9): 8358 - 8363. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Tan, L. A. McCue, and G. D. Stormo Making connections between novel transcription factors and their DNA motifs Genome Res., February 1, 2005; 15(2): 312 - 320. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. M. Keseler, J. Collado-Vides, S. Gama-Castro, J. Ingraham, S. Paley, I. T. Paulsen, M. Peralta-Gil, and P. D. Karp EcoCyc: a comprehensive database resource for Escherichia coli Nucleic Acids Res., January 1, 2005; 33(suppl_1): D334 - D337. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. von Mering, L. J. Jensen, B. Snel, S. D. Hooper, M. Krupp, M. Foglierini, N. Jouffre, M. A. Huynen, and P. Bork STRING: known and predicted protein-protein associations, integrated and transferred across organisms Nucleic Acids Res., January 1, 2005; 33(suppl_1): D433 - D437. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-W. Ma, B. Kumar, U. Ditges, F. Gunzer, J. Buer, and A.-P. Zeng An extended transcriptional regulatory network of Escherichia coli and analysis of its h |












