1per

</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1per FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1per OCA], [https://pdbe.org/1per PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1per RCSB], [https://www.ebi.ac.uk/pdbsum/1per PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1per ProSAT]</span></td></tr>

[[https://www.uniprot.org/uniprot/RPC1_BP434 RPC1_BP434]] Binds to two sets of three contiguous operator sites in the phage genome.

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== Publication Abstract from PubMed ==

BACKGROUND: The repressor of phage 434 binds to a set of operator sites as a homodimer. Its relative affinities for these sites determine the switch from lysogenic to lytic growth. The six 434 operator sites (OR1, OR2, OR3, OL1, OL2 and OL3) have a particularly simple organization; all are 14 base pairs long, with a conserved 5'-ACAA sequence symmetrically placed at either end, and a variable central six base pairs. OR3 is unique among naturally-occurring 434 operator sites in that it contains a non-consensus base pair, G.C, at the fourth position of the otherwise invariant 5'-ACAA sequence. Comparisons among structures of the 434 repressor DNA-binding domain, R1-69, bound to various operator sites, allow us to analyze differential specificity in regulatory complexes of this kind. RESULTS: We have determined the structure at 2.5 A resolution of a complex of R1-69 with DNA containing the OR3 site and compared it with previously studied complexes of R1-69 bound to OR1 and OR2. There are surprisingly extensive structural differences between the consensus and non-consensus half-sites of OR3 with respect to their interactions with R1-69, including a shift in the DNA backbone and a small rotation of the entire R1-69 monomer. CONCLUSIONS: Recognition of the base pair difference that is critical for the 434 regulatory switch involves a number of amino acid residues, not just the one or two side chains in direct contact with the G-C base pair. Moreover, the repressor imposes a somewhat altered DNA conformation on the non-consensus half-site.

The complex between phage 434 repressor DNA-binding domain and operator site OR3: structural differences between consensus and non-consensus half-sites.,Rodgers DW, Harrison SC Structure. 1993 Dec 15;1(4):227-40. PMID:8081737<ref>PMID:8081737</ref>

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

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== References ==

<references/>

[[Category: Harrison, S C]]

[[Category: Rodgers, D W]]

[[Category: Transcription-dna complex]]