Nucleic Acids Research Advance Access published online on October 25, 2007
Nucleic Acids Research, doi:10.1093/nar/gkm781
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Database Issue |
QuadBase: genome-wide database of G4 DNA—occurrence and conservation in human, chimpanzee, mouse and rat promoters and 146 microbes
1G. N. Ramachandran Knowledge Centre for Genome Informatics and 2Proteomics and Structural Biology Unit, Institute of Genomics and Integrative Biology, CSIR, New Delhi 110 007, India
* To whom correspondence should be addressed. Fax: +91 11 2766 7471; Email: shantanuc{at}igib.res.in
Received August 9, 2007. Revised September 15, 2007. Accepted September 17, 2007.
Emerging evidence indicates the importance of G-quadruplex motifs as drug targets. [Stuart A. Borman, Ascent of quadruplexes—nucleic acid structures become promising drug targets. Chem. Eng. News, 2007;85, 12–17], which stems from the fact that these motifs are present in a surprising number of promoters wherein their role in controlling gene expression has been demonstrated for a few. We present a compendium of quadruplex motifs, with particular focus on their occurrence and conservation in promoters—QuadBase. It is composed of two parts (EuQuad and ProQuad). EuQuad gives information on quadruplex motifs present within 10 kb of transcription starts sites in 99 980 human, chimpanzee, rat and mouse genes. ProQuad contains quadruplex information of 146 prokaryotes. Apart from gene-specific searches for quadruplex motifs, QuadBase has a number of other modules. ‘Orthologs Analysis’ queries for conserved motifs across species based on a selected reference organism; ‘Pattern Search’ can be used to fetch specific motifs of interest from a selected organism using user-defined criteria for quadruplex motifs, i.e. stem, loop size, etc. ‘Pattern Finder’ tool can search for motifs in any given sequence. QuadBase is freely available to users from non-profit organization at http://quadbase.igib.res.in/.