3bnk

X-ray crystal structure of Flavoredoxin from Methanosarcina acetivorans

spinqualitylabelsall models 3bnk, resolution 2.05Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3bnk is a 2 chain structure with sequence from Atcc 35395. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: FMN Gene: MA0328 (ATCC 35395) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 Flavoredoxin is a FMN-containing electron transfer protein that functions in the energy-yielding metabolism of Desulfovibrio gigas of the Bacteria domain. Although characterization of this flavoredoxin is the only one reported, a database search revealed homologues widely distributed in both the Bacteria and Archaea domains that define a novel family. To improve our understanding of this family, a flavoredoxin from Methanosarcina acetivorans of the Archaea domain was produced in Escherichia coli and biochemically characterized, and a high-resolution crystal structure was determined. The protein was shown to be a homodimer with a subunit molecular mass of 21 kDa containing one noncovalently bound FMN per monomer. Redox titration showed an E m of -271 mV with two electrons, consistent with no semiquinone observed in the potential range studied, a result suggesting the flavoredoxin functions as a two-electron carrier. However, neither of the obligate two-electron carriers, NAD(P)H and coenzyme F 420H 2, was a competent electron donor, whereas 2[4Fe-4S] ferredoxin reduced the flavoredoxin. The X-ray crystal structure determined at 2.05 A resolution revealed a homodimer containing one FMN per monomer, consistent with the biochemical characterization. The isoalloxazine ring of FMN was shown buried within a narrow groove approximately 10 A from the positively charged protein surface that possibly facilitates interaction with the negatively charged ferredoxin. The structure provides a basis for predicting the mechanism by which electrons are transferred between ferredoxin and FMN. The FMN is bound with hydrogen bonds to the isoalloxazine ring and electrostatic interactions with the phosphate moiety that, together with sequence analyses of homologues, indicate a novel FMN binding motif for the flavoredoxin family. Structural and Biochemical Characterization of Flavoredoxin from the Archaeon Methanosarcina acetivorans(,).,Suharti S, Murakami KS, de Vries S, Ferry JG Biochemistry. 2008 Nov 4;47(44):11528-11535. Epub 2008 Oct 9. PMID:18842001 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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