Structural insights from a P450 Carrier Protein complex reveal how specificity is achieved in the P450(BioI) ACP complex.
Cytochrome P450(BioI) (CYP107H1) from the biotin operon of Bacillus subtilis forms a seven-carbon diacid through a multistep oxidative cleavage of a fatty acid linked to acyl carrier protein (ACP). Crystal structures of P450(BioI) in complex with three different length fatty acyl-ACP (Escherichia coli) ligands show that P450(BioI) binds the fatty acid such as to force the carbon chain into a U-shape above the active site heme. This positions the C7 and C8 carbons for oxidation, with a large additional cavity extending beyond the heme to accommodate the methyl termini of fatty acids beyond the site of cleavage. The structures explain the experimentally observed lack of stereo- and regiospecificity in the hydroxylation and cleavage of free fatty acids. The P450(BioI)-ACP complexes represent the only structurally characterized P450-carrier protein complexes to date, which has allowed the generation of a model of the interaction of the vancomycin biosynthetic P450 OxyB with its proposed carrier protein bound substrate.
Cryle
Max J
MJ
Department of Biomolecular Mechanisms, Max-Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany. Max.Cryle@mpimf-heidelberg.mpg.de
Schlichting
Ilme
I
D000213:Acyl Carrier Protein / Q000737:chemistry* / Q000378:metabolism; D001412:Bacillus subtilis / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D015394:Molecular Structure; D011487:Protein Conformation; D014640:Vancomycin
D000213:Acyl Carrier Protein; D001426:Bacterial Proteins; D005227:Fatty Acids; D008024:Ligands; D014640:Vancomycin; D003577:Cytochrome P-450 Enzyme System; C483260:CYP107H1, Bacillus subtilis