1KU2

Crystal Structure of Thermus aquaticus RNA Polymerase Sigma Subunit Fragment Containing Regions 1.2 to 3.1

Summary for 1KU2

• Entry DOI: 10.2210/pdb1ku2/pdb
• Related: 1ku3 1ku7
• Descriptor: sigma factor sigA, SULFATE ION (2 entities in total)
• Functional Keywords: helices, transcription
• Biological source: Thermus aquaticus
• Total number of polymer chains: 2
• Total formula weight: 55421.90

Authors

Campbell, E.A.,Muzzin, O.,Chlenov, M.,Sun, J.L.,Olson, C.A.,Weinman, O.,Trester-Zedlitz, M.L.,Darst, S.A. (deposition date: 2002-01-21, release date: 2002-04-03, Last modification date: 2024-02-14)

Primary citation

Campbell, E.A.,Muzzin, O.,Chlenov, M.,Sun, J.L.,Olson, C.A.,Weinman, O.,Trester-Zedlitz, M.L.,Darst, S.A.
Structure of the bacterial RNA polymerase promoter specificity sigma subunit.
Mol.Cell, 9:527-539, 2002

PubMed Abstract: 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.

PubMed: 11931761
DOI: 10.1016/S1097-2765(02)00470-7

Experimental method

X-RAY DIFFRACTION (2.9 Å)