3hq7 | pdb_00003hq7

CcpA from G. sulfurreducens, G94K/K97Q/R100I variant

spinqualitylabelsall models 3hq7, resolution 2.31Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3hq7 is a 1 chain structure with sequence from Geobacter sulfurreducens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.31Å Ligands: CA, HEM Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q749D0_GEOSL 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 Bacterial di-heme cytochrome c peroxidases (CcpAs) protect the cell from reactive oxygen species by reducing hydrogen peroxide to water. The enzymes are c-type cytochromes, with both heme groups covalently attached to the protein chain via a characteristic binding motif. The genome of the dissimilatory metal-reducing bacterium Geobacter sulfurreducens revealed the presence of a ccpA gene and we isolated the gene product after recombinant expression in Escherichia coli. CcpA from G. sulfurreducens exhibited in vitro peroxidase activity with ABTS(2-) [2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)] as an electron donor, and the three-dimensional structure of the dimeric enzyme has been determined to high resolution. For activation, CcpA commonly requires reduction, with the exception of the Nitrosomonas europaea enzyme that retains its activity in the oxidized state. A G94K/K97Q/R100I triple point mutant was created to mimic the critical loop region of N. europaea CcpA, but its crystal structure revealed that the inactive, bis-histidinyl-coordinated form of the active-site heme group was retained. Subsequent mutational studies thus addressed an adjacent loop region, where a change in secondary structure accompanies the reductive activation of the enzyme. While an A124K/K128A double mutant did not show significant changes, the CcpA variants S134P/V135K and S134P led to a distortion of the loop region, accompanied by an opening of the active-site loop, leaving the enzyme in a constitutively active state. CcpA from Geobacter sulfurreducens is a basic di-heme cytochrome c peroxidase.,Hoffmann M, Seidel J, Einsle O J Mol Biol. 2009 Nov 6;393(4):951-65. Epub 2009 Sep 6. PMID:19735665 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome c peroxidase 3D structures

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