P450camr, a cytochrome P450 catalysing the stereospecific 6-endo-hydroxylation of (1R)-(+)-camphor

Rhodococcus sp. NCIMB 9784 accumulated 6-endo-hydroxycamphor 3 when grown on (1R)-(+)-camphor 1 as sole carbon source. The structure of 3 has been unambiguously assigned for the first time using X-ray crystallography. A soluble cytochrome P450 hydroxylase, induced by growth on (1R)-(+)-camphor and designated P450^sub camr^, has been isolated from the bacterium Rhodococcus sp. NCIMB 9784. Using authentic 6-endo hydroxycamphor as standard, a cell-free system consisting of pure P450^sub camr^ and putidaredoxin and putidaredoxin reductase from Pseudomonas putida confirmed that the enzyme hydroxylates (1R)-(+)-camphor specifically in the 6-endo position, in contrast to the 5-exo hydroxylation catalysed by the well-studied P450^sub cam^ from P. putida. P450^sub camr^ has a molecular mass of approximately 44 kDa, and a pI of 4.8.[PUBLICATION ABSTRACT]