1ku2

<table><tr><td colspan='2'>[[1ku2]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Atcc_25104 Atcc 25104]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KU2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KU2 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1ku3|1ku3]], [[1ku7|1ku7]]</div></td></tr>

[[https://www.uniprot.org/uniprot/Q9EZJ8_THEAQ Q9EZJ8_THEAQ]] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released (By similarity).[RuleBase:RU000715]

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== Publication Abstract from PubMed ==

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.

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<ref>PMID:11931761</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1ku2" style="background-color:#fffaf0;"></div>

[[Category: Atcc 25104]]

[[Category: Campbell, E A]]

[[Category: Chlenov, M]]

[[Category: Darst, S A]]

[[Category: Muzzin, O]]

[[Category: Olson, C A]]

[[Category: Sun, J L]]

[[Category: Trester-Zedlitz, M L]]

[[Category: Weinman, O]]

[[Category: Transcription]]