View source for 1nla


==Solution Structure of Switch Arc, a Mutant with 3(10) Helices Replacing a Wild-Type Beta-Ribbon==
<StructureSection load='1nla' size='340' side='right'caption='[[1nla]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1nla]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_virus_P22 Salmonella virus P22]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NLA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NLA 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=1nla FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nla OCA], [https://pdbe.org/1nla PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1nla RCSB], [https://www.ebi.ac.uk/pdbsum/1nla PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1nla ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RARC_BPP22 RARC_BPP22] This protein acts as a transcriptional repressor of its own gene arc and of gene ant.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Adjacent N11L and L12N mutations in the antiparallel beta-ribbon of Arc repressor result in dramatic changes in local structure in which each beta-strand is replaced by a right-handed helix. The full solution structure of this "switch" Arc mutant shows that irregular 3(10) helices compose the new secondary structure. This structural metamorphosis conserves the number of main-chain and side-chain to main-chain hydrogen bonds and the number of fully buried core residues. Apart from a slight widening of the interhelical angle between alpha-helices A and B and changes in side-chain conformation of a few core residues in Arc, no large-scale structural adjustments in the remainder of the protein are necessary to accommodate the ribbon-to-helix change. Nevertheless, some changes in hydrogen-exchange rates are observed, even in regions that have very similar structures in the two proteins. The surface of switch Arc is packed poorly compared to wild-type, leading to approximately 1000A(2) of additional solvent-accessible surface area, and the N termini of the 3(10) helices make unfavorable head-to-head electrostatic interactions. These structural features account for the positive m value and salt dependence of the ribbon-to-helix transition in Arc-N11L, a variant that can adopt either the mutant or wild-type structures. The tertiary fold is capped in different ways in switch and wild-type Arc, showing how stepwise evolutionary transformations can arise through small changes in amino acid sequence.

Solution structure of switch Arc, a mutant with 3(10) helices replacing a wild-type beta-ribbon.,Cordes MH, Walsh NP, McKnight CJ, Sauer RT J Mol Biol. 2003 Feb 21;326(3):899-909. PMID:12581649<ref>PMID:12581649</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1nla" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Salmonella virus P22]]
[[Category: Cordes MH]]
[[Category: McKnight CJ]]
[[Category: Sauer RT]]
[[Category: Walsh NP]]