View source for 2a63


==Solution structure of a stably monomeric mutant of lambda Cro produced by substitutions in the ball-and-socket interface==
<StructureSection load='2a63' size='340' side='right'caption='[[2a63]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2a63]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_virus_Lambda Escherichia virus Lambda]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A63 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2A63 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</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=2a63 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2a63 OCA], [https://pdbe.org/2a63 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2a63 RCSB], [https://www.ebi.ac.uk/pdbsum/2a63 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2a63 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RCRO_LAMBD RCRO_LAMBD] Cro represses genes normally expressed in early phage development and is necessary for the late stage of lytic growth. It does this by binding to the OL and OR operators regions normally used by the repressor protein for lysogenic maintenance.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/a6/2a63_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2a63 ConSurf].
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== Publication Abstract from PubMed ==
The homodimeric lambda Cro protein has a "ball-and-socket" interface that includes insertion of an aromatic side chain, Phe 58, from each subunit into a cavity in the hydrophobic core of the other subunit. This overlap between the subunit core and dimer interface hypothetically explains the strong dimerization and weak monomer stability of lambda Cro in comparison to homologues. According to a model developed here and in a previous study [LeFevre, K. R., and Cordes, M. H. (2003) Proc. Natl. Acad. Sci. U.S.A. 100, 2345-2350], the socket cavity evolved in part by replacement of a buried tryptophan in an ancestral stable monomer with a smaller side chain (Ala 33 in lambda Cro). The resulting core defect was in effect repaired by insertion of a different side chain (Phe 58) from a second subunit, generating the ball and socket. Consistent with such an evolutionary trade between intrasubunit and intersubunit interactions, we showed in the previous study that restoration of the ancestral Trp 33 in lambda Cro stabilized the monomer and reduced the extent of dimerization. Here, we report the solution structure of a stable lambda Cro monomer containing the Ala33Trp mutation, which confirms that the restored tryptophan fulfills its ancestral role as a core side chain, filling part of the socket cavity occupied by Phe 58 in the wild-type dimer. The structure also reveals, however, that the cavity is not completely filled by Trp 33, suggesting that its formation could have involved multiple mutations that reduced side chain volume. We offer suggestive evidence of a role of mutations at a second position.

A trade between similar but nonequivalent intrasubunit and intersubunit contacts in Cro dimer evolution.,Newlove T, Atkinson KR, Van Dorn LO, Cordes MH Biochemistry. 2006 May 23;45(20):6379-91. PMID:16700549<ref>PMID:16700549</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia virus Lambda]]
[[Category: Large Structures]]
[[Category: Atkinson KR]]
[[Category: Cordes MH]]
[[Category: Newlove T]]
[[Category: Van Dorn LO]]