2hi7: Difference between revisions

Revision as of 18:42, 21 February 2008

Crystal structure of DsbA-DsbB-ubiquinone complex

OverviewOverview

Oxidation of cysteine pairs to disulfide requires cellular factors present in the bacterial periplasmic space. DsbB is an E. coli membrane protein that oxidizes DsbA, a periplasmic dithiol oxidase. To gain insight into disulfide bond formation, we determined the crystal structure of the DsbB-DsbA complex at 3.7 A resolution. The structure of DsbB revealed four transmembrane helices and one short horizontal helix juxtaposed with Cys130 in the mobile periplasmic loop. Whereas DsbB in the resting state contains a Cys104-Cys130 disulfide, Cys104 in the binary complex is engaged in the intermolecular disulfide bond and captured by the hydrophobic groove of DsbA, resulting in separation from Cys130. This cysteine relocation prevents the backward resolution of the complex and allows Cys130 to approach and activate the disulfide-generating reaction center composed of Cys41, Cys44, Arg48, and ubiquinone. We propose that DsbB is converted by its specific substrate, DsbA, to a superoxidizing enzyme, capable of oxidizing this extremely oxidizing oxidase.

About this StructureAbout this Structure

2HI7 is a Protein complex structure of sequences from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structure of the DsbB-DsbA complex reveals a mechanism of disulfide bond generation., Inaba K, Murakami S, Suzuki M, Nakagawa A, Yamashita E, Okada K, Ito K, Cell. 2006 Nov 17;127(4):789-801. PMID:17110337

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OCA

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-[[Image:2hi7.gif|left|200px]]<br /><applet load="2hi7" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2hi7.gif|left|200px]]<br /><applet load="2hi7" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2hi7, resolution 3.70&Aring;" />
 '''Crystal structure of DsbA-DsbB-ubiquinone complex'''<br />
 ==Overview==
-Oxidation of cysteine pairs to disulfide requires cellular factors present, in the bacterial periplasmic space. DsbB is an E. coli membrane protein, that oxidizes DsbA, a periplasmic dithiol oxidase. To gain insight into, disulfide bond formation, we determined the crystal structure of the, DsbB-DsbA complex at 3.7 A resolution. The structure of DsbB revealed four, transmembrane helices and one short horizontal helix juxtaposed with, Cys130 in the mobile periplasmic loop. Whereas DsbB in the resting state, contains a Cys104-Cys130 disulfide, Cys104 in the binary complex is, engaged in the intermolecular disulfide bond and captured by the, hydrophobic groove of DsbA, resulting in separation from Cys130. This, cysteine relocation prevents the backward resolution of the complex and, allows Cys130 to approach and activate the disulfide-generating reaction, center composed of Cys41, Cys44, Arg48, and ubiquinone. We propose that, DsbB is converted by its specific substrate, DsbA, to a superoxidizing, enzyme, capable of oxidizing this extremely oxidizing oxidase.
+Oxidation of cysteine pairs to disulfide requires cellular factors present in the bacterial periplasmic space. DsbB is an E. coli membrane protein that oxidizes DsbA, a periplasmic dithiol oxidase. To gain insight into disulfide bond formation, we determined the crystal structure of the DsbB-DsbA complex at 3.7 A resolution. The structure of DsbB revealed four transmembrane helices and one short horizontal helix juxtaposed with Cys130 in the mobile periplasmic loop. Whereas DsbB in the resting state contains a Cys104-Cys130 disulfide, Cys104 in the binary complex is engaged in the intermolecular disulfide bond and captured by the hydrophobic groove of DsbA, resulting in separation from Cys130. This cysteine relocation prevents the backward resolution of the complex and allows Cys130 to approach and activate the disulfide-generating reaction center composed of Cys41, Cys44, Arg48, and ubiquinone. We propose that DsbB is converted by its specific substrate, DsbA, to a superoxidizing enzyme, capable of oxidizing this extremely oxidizing oxidase.
 ==About this Structure==
-HI7 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ZN and UQ1 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2HI7 OCA].
+HI7 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=UQ1:'>UQ1</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HI7 OCA].
 ==Reference==
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 [[Category: ubiquinone]]
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