3cbd | pdb_00003cbd

Directed Evolution of cytochrome P450 BM3, to octane monoxygenase 139-3

spinqualitylabelsall models 3cbd, resolution 2.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3cbd is a 2 chain structure with sequence from Bacillus megaterium. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 140, HEM Related: 1jpz, 1zoa, 1zo9, 1fag Gene: CYP102 (Bacillus megaterium) Activity: Unspecific monooxygenase, with EC number 1.14.14.1 Resources: FirstGlance, OCA, RCSB, PDBsum 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 evolutionary pressures that shaped the specificity and catalytic efficiency of enzymes can only be speculated. While directed evolution experiments show that new functions can be acquired under positive selection with few mutations, the role of negative selection in eliminating undesired activities and achieving high specificity remains unclear. Here we examine intermediates along the 'lineage' from a naturally occurring C12-C20 fatty acid hydroxylase (P450BM3) to a laboratory-evolved P450 propane monooxygenase (P450PMO) having 20 heme domain substitutions compared to P450BM3. Biochemical, crystallographic, and computational analyses show that a minimal perturbation of the P450BM3 fold and substrate-binding pocket accompanies a significant broadening of enzyme substrate range and the emergence of propane activity. In contrast, refinement of the enzyme catalytic efficiency for propane oxidation (approximately 9000-fold increase in kcat/Km) involves profound reshaping and partitioning of the substrate access pathway. Remodeling of the substrate-recognition mechanisms ultimately results in remarkable narrowing of the substrate profile around propane and enables the acquisition of a basal iodomethane dehalogenase activity as yet unknown in natural alkane monooxygenases. A highly destabilizing L188P substitution in a region of the enzyme that undergoes a large conformational change during catalysis plays an important role in adaptation to the gaseous alkane. This work demonstrates that positive selection alone is sufficient to completely respecialize the cytochrome P450 for function on a nonnative substrate. Evolutionary history of a specialized p450 propane monooxygenase.,Fasan R, Meharenna YT, Snow CD, Poulos TL, Arnold FH J Mol Biol. 2008 Nov 28;383(5):1069-80. Epub 2008 Jun 28. PMID:18619466 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome P450 Escherichia coli LepA%2C the ribosomal back translocase

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