1ku3
From Proteopedia
Crystal Structure of Thermus aquaticus RNA Polymerase Sigma Subunit Fragment, Region 4
Overview
The sigma subunit is the key regulator of bacterial transcription. Proteolysis of Thermus aquaticus sigma(A), which occurred in situ during crystallization, reveals three domains, sigma(2), sigma(3), and sigma(4), connected by flexible linkers. Crystal structures of each domain were determined, as well as of sigma(4) complexed with -35 element DNA. Exposed surfaces of each domain are important for RNA polymerase binding. Universally conserved residues important for -10 element recognition and melting lie on one face of sigma(2), while residues important for extended -10 recognition lie on sigma(3). Genetic studies correctly predicted that a helix-turn-helix motif in sigma(4) recognizes the -35 element but not the details of the protein-DNA interactions. Positive control mutants in sigma(4) cluster in two regions, positioned to interact with activators bound just upstream or downstream of the -35 element.
About this Structure
1KU3 is a Single protein structure of sequence from Thermus aquaticus. Full crystallographic information is available from OCA.
Reference
Structure of the bacterial RNA polymerase promoter specificity sigma subunit., Campbell EA, Muzzin O, Chlenov M, Sun JL, Olson CA, Weinman O, Trester-Zedlitz ML, Darst SA, Mol Cell. 2002 Mar;9(3):527-39. PMID:11931761 Page seeded by OCA on Fri May 2 23:10:25 2008
