2h27
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="2h27" size="450" color="white" frame="true" align="right" spinBox="true" caption="2h27, resolution 2.30Å" /> '''Crystal Structure of...)
Next diff →
Revision as of 09:23, 21 November 2007
|
Crystal Structure of Escherichia coli SigmaE Region 4 Bound to its-35 Element DNA
Overview
The control of bacterial transcription initiation depends on a primary, sigma factor for housekeeping functions, as well as alternative sigma, factors that control regulons in response to environmental stresses. The, largest and most diverse subgroup of alternative sigma factors, the group, IV extracytoplasmic function sigma factors, directs the transcription of, genes that regulate a wide variety of responses, including envelope stress, and pathogenesis. We determined the 2.3-A resolution crystal structure of, the -35 element recognition domain of a group IV sigma factor, Escherichia, coli sigma(E)4, bound to its consensus -35 element, GGAACTT. Despite, similar function and secondary structure, the primary and group IV sigma, factors recognize their -35 elements using distinct mechanisms. Conserved, sequence elements of the sigma(E) -35 element induce a DNA geometry, characteristic of AA/TT-tract DNA, including a rigid, straight, double-helical axis and a narrow minor groove. For this reason, the highly, conserved AA in the middle of the GGAACTT motif is essential for -35, element recognition by sigma(E)4, despite the absence of direct, protein-DNA interactions with these DNA bases. These principles of, sigma(E)4/-35 element recognition can be applied to a wide range of other, group IV sigma factors.
About this Structure
2H27 is a Single protein structure of sequence from Escherichia coli with MPD as ligand. Full crystallographic information is available from OCA.
Reference
The structural basis for promoter -35 element recognition by the group IV sigma factors., Lane WJ, Darst SA, PLoS Biol. 2006 Sep;4(9):e269. PMID:16903784
Page seeded by OCA on Wed Nov 21 11:30:37 2007
