Nucleic Acids Research, Vol 26, Issue 11 2723-2728, Copyright © 1998 by Oxford University Press
V Serebrov, K Vassilenko, N Kholod, HJ Gross and L Kisselev
Mature tRNAPhe from Escherichia coli and the transcript of its gene lacking
modified nucleotides were compared by a variety of physical techniques.
Melting experiments revealed that at a low Mg2+level the transcript was
partially denatured, while the mature tRNA possessed intact tertiary
interactions. Mg2+binding to both tRNAs was studied by CD and UV techniques
as well as by using the Mg2+-sensitive fluorescence indicator,
8-hydroxyquinoline 5-sulfonic acid. Both tRNA forms exhibited a single
strong Mg2+-binding site, its dissociation constant was 10-fold higher for
the transcript. Conformational changes in response to Mg2+ addition
measured by CD and UV spectrometry revealed no difference for the estimated
binding cooperativity and strong differences for affinities of Mg2+-binding
sites for the two tRNA forms. Conformational transitions in mature and in
in vitro synthesized tRNA required the binding of two Mg2+ ions per
molecule and therefore should be associated not only with a single strong
binding site. The Mg2+ dependence of Stokes radii measured by
gel-filtration revealed insignificant differences between the overall sizes
of the two tRNA forms at physiological Mg2+ levels (>1 mM). Taken
together, these results suggest that modified nucleotides stabilize
tertiary interactions and increase the structure stability without
affecting the mechanism of Mg2+binding and overall folding of the tRNA
molecule. This conclusion is supported by the known biological activity of
the E. coli tRNAPhe gene transcript.
ARTICLES
Mg2+ binding and structural stability of mature and in vitro synthesized unmodified Escherichia coli tRNAPhe
Engelhardt Institute of Molecular Biology, Moscow 117984, Russia.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  R. Oliva, A. Tramontano, and L. Cavallo Mg2+ binding and archaeosine modification stabilize the G15 C48 Levitt base pair in tRNAs RNA, September 1, 2007; 13(9): 1427 - 1436. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. A. COPELA, G. CHAKSHUSMATHI, R. L. SHERRER, and S. L. WOLIN The La protein functions redundantly with tRNA modification enzymes to ensure tRNA structural stability. RNA, April 1, 2006; 12(4): 644 - 654. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Rolle, M. Zywicki, E. Wyszko, M. Z. Barciszewska, and J. Barciszewski Evaluation of the Dynamic Structure of DsrA RNA from E. coli and Its Functional Consequences. J. Biochem., March 1, 2006; 139(3): 431 - 438. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Helm Post-transcriptional nucleotide modification and alternative folding of RNA Nucleic Acids Res., February 1, 2006; 34(2): 721 - 733. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. M. Wilson, K. Sutphen, K.-y. Chuang, and G. Brewer Folding of A+U-rich RNA Elements Modulates AUF1 Binding. POTENTIAL ROLES IN REGULATION OF mRNA TURNOVER J. Biol. Chem., March 16, 2001; 276(12): 8695 - 8704. [Abstract] [Full Text] [PDF]
|
|