Structural characterization of CalO2: a putative orsellinic acid P450 oxidase in the calicheamicin biosynthetic pathway.
Although bacterial iterative Type I polyketide synthases are now known to participate in the biosynthesis of a small set of diverse natural products, the subsequent downstream modification of the resulting polyketide products remains poorly understood. Toward this goal, we report the X-ray structure determination at 2.5 A resolution and preliminary characterization of the putative orsellenic acid P450 oxidase (CalO2) involved in calicheamicin biosynthesis. These studies represent the first crystal structure for a P450 involved in modifying a bacterial iterative Type I polyketide product and suggest the CalO2-catalyzed step may occur after CalO3-catalyzed iodination and may also require a coenzyme A- (CoA) or acyl carrier protein- (ACP) bound substrate. Docking studies also reveal a putative docking site within CalO2 for the CLM orsellinic acid synthase (CalO5) ACP domain which involves a well-ordered helix along the CalO2 active site cavity that is unique compared with other P450 structures.
Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706-1544, USA.
Jason G
JG
McCoy
Heather D
HD
Johnson
Shanteri
S
Singh
Craig A
CA
Bingman
In-Kyoung
IK
Lei
Jon S
JS
Thorson
George N
GN
Phillips
D000213:Acyl Carrier Protein / Q000378:metabolism; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D053898:Biosynthetic Pathways; D003065:Coenzyme A / Q000378:metabolism; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics; D007455:Iodine / Q000378:metabolism; D008024:Ligands; D008847:Micromonospora / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D048630:Polyketide Synthases / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012118:Resorcinols / Q000378:metabolism; D013302:Streptomyces / Q000235:genetics
D000213:Acyl Carrier Protein; D001426:Bacterial Proteins; D008024:Ligands; D012118:Resorcinols; C501612:orsellinic acid; D048630:Polyketide Synthases; D007455:Iodine; D010088:Oxidoreductases; D003065:Coenzyme A