View source for 1ac1


==DSBA MUTANT H32L==
<StructureSection load='1ac1' size='340' side='right'caption='[[1ac1]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ac1]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AC1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AC1 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2&#8491;</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=1ac1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ac1 OCA], [https://pdbe.org/1ac1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ac1 RCSB], [https://www.ebi.ac.uk/pdbsum/1ac1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ac1 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DSBA_ECOLI DSBA_ECOLI] Required for disulfide bond formation in some periplasmic proteins such as PhoA or OmpA. Acts by transferring its disulfide bond to other proteins and is reduced in the process. DsbA is reoxidized by DsbB. Required for pilus biogenesis. PhoP-regulated transcription is redox-sensitive, being activated when the periplasm becomes more reducing (deletion of dsbA/dsbB, treatment with dithiothreitol). MgrB acts between DsbA/DsbB and PhoP/PhoQ in this pathway.<ref>PMID:1429594</ref> <ref>PMID:22267510</ref> 
== 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/ac/1ac1_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1ac1 ConSurf].
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== Publication Abstract from PubMed ==
DsbA, a 21-kDa protein from Escherichia coli, is a potent oxidizing disulfide catalyst required for disulfide bond formation in secreted proteins. The active site of DsbA is similar to that of mammalian protein disulfide isomerases, and includes a reversible disulfide bond formed from cysteines separated by two residues (Cys30-Pro31-His32-Cys33). Unlike most protein disulfides, the active-site disulfide of DsbA is highly reactive and the oxidized form of DsbA is much less stable than the reduced form at physiological pH. His32, one of the two residues between the active-site cysteines, is critical to the oxidizing power of DsbA and to the relative instability of the protein in the oxidized form. Mutation of this single residue to tyrosine, serine, or leucine results in a significant increase in stability (of approximately 5-7 kcal/mol) of the oxidized His32 variants relative to the oxidized wild-type protein. Despite the dramatic changes in stability, the structures of all three oxidized DsbA His32 variants are very similar to the wild-type oxidized structure, including conservation of solvent atoms near the active-site residue, Cys30. These results show that the His32 residue does not exert a conformational effect on the structure of DsbA. The destabilizing effect of His32 on oxidized DsbA is therefore most likely electrostatic in nature.

Structural analysis of three His32 mutants of DsbA: support for an electrostatic role of His32 in DsbA stability.,Guddat LW, Bardwell JC, Glockshuber R, Huber-Wunderlich M, Zander T, Martin JL Protein Sci. 1997 Sep;6(9):1893-900. PMID:9300489<ref>PMID:9300489</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Guddat LW]]
[[Category: Martin JL]]