3ics | pdb_00003ics

Crystal structure of partially reduced Bacillus anthracis CoADR-RHD

spinqualitylabelsall models 3ics, resolution 1.94Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3ics is a 2 chain structure with sequence from Bacillus anthracis str. Ames. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.94Å Ligands: ADP, COA, FAD, MSE Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function A0A6L7H7X4_BACAN Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Rhodanese homology domains (RHDs) play important roles in sulfur trafficking mechanisms essential to the biosynthesis of sulfur-containing cofactors and nucleosides. We have now determined the crystal structure at 2.10 A resolution for the Bacillus anthracis coenzyme A-disulfide reductase isoform (BaCoADR-RHD) containing a C-terminal RHD domain; this is the first structural representative of the multidomain proteins class of the rhodanese superfamily. The catalytic Cys44 of the CoADR module is separated by 25 A from the active-site Cys514' of the RHD domain from the complementary subunit. In stark contrast to the B. anthracis CoADR [Wallen, J. R., Paige, C., Mallett, T. C., Karplus, P. A., and Claiborne, A. (2008) Biochemistry 47, 5182-5193], the BaCoADR-RHD isoform does not catalyze the reduction of coenzyme A-disulfide, although both enzymes conserve the Cys-SSCoA redox center. NADH titrations have been combined with a synchrotron reduction protocol for examination of the structural and redox behavior of the Cys44-SSCoA center. The synchrotron-reduced (Cys44 + CoASH) structure reveals ordered binding for the adenosine 3'-phosphate 5'-pyrophosphate moiety of CoASH, but the absence of density for the pantetheine arm indicates that it is flexible within the reduced active site. Steady-state kinetic analyses with the alternate disulfide substrates methyl methanethiolsulfonate (MMTS) and 5,5'-dithiobis(2-nitrobenzoate) (DTNB), including the appropriate Cys --> Ser mutants, demonstrate that MMTS reduction occurs within the CoADR active site. NADH-dependent DTNB reduction, on the other hand, requires communication between Cys44 and Cys514', and we propose that reduction of the Cys44-SSCoA disulfide promotes the transfer of reducing equivalents to the RHD, with the swinging pantetheine arm serving as a ca. 20 A bridge. Crystal structure and catalytic properties of Bacillus anthracis CoADR-RHD: implications for flavin-linked sulfur trafficking.,Wallen JR, Mallett TC, Boles W, Parsonage D, Furdui CM, Karplus PA, Claiborne A Biochemistry. 2009 Oct 13;48(40):9650-67. PMID:19725515 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Coenzyme A-Disulfide Reductase

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