Publication Date:
2002-05-23
Description:
The crystal structure of the initiating form of Thermus aquaticus RNA polymerase, containing core RNA polymerase (alpha2betabeta'omega) and the promoter specificity sigma subunit, has been determined at 4 angstrom resolution. Important structural features of the RNA polymerase and their roles in positioning sigma within the initiation complex are delineated, as well as the role played by sigma in modulating the opening of the RNA polymerase active-site channel. The two carboxyl-terminal domains of sigma are separated by 45 angstroms on the surface of the RNA polymerase, but are linked by an extended loop. The loop winds near the RNA polymerase active site, where it may play a role in initiating nucleotide substrate binding, and out through the RNA exit channel. The advancing RNA transcript must displace the loop, leading to abortive initiation and ultimately to sigma release.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Murakami, Katsuhiko S -- Masuda, Shoko -- Darst, Seth A -- GM53759/GM/NIGMS NIH HHS/ -- GM61898/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2002 May 17;296(5571):1280-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12016306" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Motifs
;
Binding Sites
;
Crystallization
;
Crystallography, X-Ray
;
DNA, Bacterial/metabolism
;
DNA-Directed RNA Polymerases/*chemistry/*metabolism
;
Eukaryotic Cells/metabolism
;
Holoenzymes/chemistry/metabolism
;
Models, Molecular
;
Promoter Regions, Genetic
;
Protein Conformation
;
Protein Structure, Quaternary
;
Protein Structure, Secondary
;
Protein Structure, Tertiary
;
RNA, Bacterial/metabolism
;
RNA, Messenger/metabolism
;
Sigma Factor/metabolism
;
Thermus/*enzymology
;
*Transcription, Genetic
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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