1smi

A single mutation of P450 BM3 induces the conformational rearrangement seen upon substrate-binding in wild-type enzyme

spinqualitylabelsall models 1smi, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1smi 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 2Å 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 The multidomain fatty-acid hydroxylase flavocytochrome P450 BM3 has been studied as a paradigm model for eukaryotic microsomal P450 enzymes because of its homology to eukaryotic family 4 P450 enzymes and its use of a eukaryotic-like diflavin reductase redox partner. High-resolution crystal structures have led to the proposal that substrate-induced conformational changes lead to removal of water as the sixth ligand to the heme iron. Concomitant changes in the heme iron spin state and heme iron reduction potential help to trigger electron transfer from the reductase and to initiate catalysis. Surprisingly, the crystal structure of the substrate-free A264E heme domain mutant reveals the enzyme to be in the conformation observed for substrate-bound wild-type P450, but with the iron in the low-spin state. This provides strong evidence that the spin-state shift observed upon substrate binding in wild-type P450 BM3 not only is caused indirectly by structural changes in the protein, but is a direct consequence of the presence of the substrate itself, similar to what has been observed for P450cam. The crystal structure of the palmitoleate-bound A264E mutant reveals that substrate binding promotes heme ligation by Glu(264), with little other difference from the palmitoleate-bound wild-type structure observable. Despite having a protein-derived sixth heme ligand in the substrate-bound form, the A264E mutant is catalytically active, providing further indication for structural rearrangement of the active site upon reduction of the heme iron, including displacement of the glutamate ligand to allow binding of dioxygen. A single mutation in cytochrome P450 BM3 induces the conformational rearrangement seen upon substrate binding in the wild-type enzyme.,Joyce MG, Girvan HM, Munro AW, Leys D J Biol Chem. 2004 May 28;279(22):23287-93. Epub 2004 Mar 12. PMID:15020590 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome P450 3D structures

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