2ij3

Structure of the A264H mutant of cytochrome P450 BM3

spinqualitylabelsall models 2ij3, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ij3 is a 2 chain structure with sequence from Priestia megaterium. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: HEM Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CPXB_PRIM2 Functions as a fatty acid monooxygenase (PubMed:11695892, PubMed:14653735, PubMed:16403573, PubMed:16566047, PubMed:17077084, PubMed:1727637, PubMed:17868686, PubMed:18004886, PubMed:18298086, PubMed:18619466, PubMed:18721129, PubMed:19492389, PubMed:20180779, PubMed:21110374, PubMed:21875028, PubMed:3106359, PubMed:7578081). Catalyzes hydroxylation of fatty acids at omega-1, omega-2 and omega-3 positions (PubMed:1727637, PubMed:21875028). Shows activity toward medium and long-chain fatty acids, with optimum chain lengths of 12, 14 and 16 carbons (lauric, myristic, and palmitic acids). Able to metabolize some of these primary metabolites to secondary and tertiary products (PubMed:1727637). Marginal activity towards short chain lengths of 8-10 carbons (PubMed:1727637, PubMed:18619466). Hydroxylates highly branched fatty acids, which play an essential role in membrane fluidity regulation (PubMed:16566047). Also displays a NADPH-dependent reductase activity in the C-terminal domain, which allows electron transfer from NADPH to the heme iron of the cytochrome P450 N-terminal domain (PubMed:11695892, PubMed:14653735, PubMed:16403573, PubMed:16566047, PubMed:17077084, PubMed:1727637, PubMed:17868686, PubMed:18004886, PubMed:18298086, PubMed:18619466, PubMed:18721129, PubMed:19492389, PubMed:20180779, PubMed:21110374, PubMed:21875028, PubMed:3106359, PubMed:7578081). Involved in inactivation of quorum sensing signals of other competing bacteria by oxidazing efficiently acyl homoserine lactones (AHLs), molecules involved in quorum sensing signaling pathways, and their lactonolysis products acyl homoserines (AHs) (PubMed:18020460). 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 Two novel P450 heme iron ligand sets were generated by directed mutagenesis of the flavocytochrome P450 BM3 heme domain. The A264H and A264K variants produce Cys-Fe-His and Cys-Fe-Lys axial ligand sets, which were validated structurally and characterized by spectroscopic analysis. EPR and magnetic circular dichroism (MCD) provided fingerprints defining these P450 ligand sets. Near IR MCD spectra identified ferric low spin charge-transfer bands diagnostic of the novel ligands. For the A264K mutant, this is the first report of a Cys-Fe-Lys near-IR MCD band. Crystal structure determination showed that substrate-free A264H and A264K proteins crystallize in distinct conformations, as observed previously in substrate-free and fatty acid-bound wild-type P450 forms, respectively. This, in turn, likely reflects the positioning of the I alpha helix section of the protein that is required for optimal configuration of the ligands to the heme iron. One of the monomers in the asymmetric unit of the A264H crystals was in a novel conformation with a more open substrate access route to the active site. The same species was isolated for the wildtype heme domain and represents a novel conformational state of BM3 (termed SF2). The "locking" of these distinct conformations is evident from the fact that the endogenous ligands cannot be displaced by substrate or exogenous ligands. The consequent reduction of heme domain conformational heterogeneity will be important in attempts to determine atomic structure of the full-length, multidomain flavocytochrome, and thus to understand in atomic detail interactions between its heme and reductase domains. Structural and spectroscopic characterization of P450 BM3 mutants with unprecedented P450 heme iron ligand sets. New heme ligation states influence conformational equilibria in P450 BM3.,Girvan HM, Seward HE, Toogood HS, Cheesman MR, Leys D, Munro AW J Biol Chem. 2007 Jan 5;282(1):564-72. Epub 2006 Oct 31. PMID:17077084 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome P450 3D structures

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