    4.2.1.100 | metabolism |
the enzyme is involved in the biodegradation of the environmentally hazardous fluoroaromatics. The 1,5-dienoyl-CoA hydratase (DCH) hydrates the fluoro-1,5-dienoyl-CoA isomers to a mixture of the stable 2-fluoro-6-hydroxy-1-enoyl-CoA and the unstable alpha-fluorohydrin 6-fluoro-6-hydroxy-1-enoyl-CoA. The latter spontaneously decomposes to HF and 6-oxo-cyclohex-1-enoyl-CoA, a common intermediate of the benzoyl-coenzyme A (BzCoA) degradation pathway. 6-Oxo-cyclohex-1-enoyl-CoA hydrolase/hydratase catalyzes the defluorination of 2-fluoro-6-hydroxycyclohex-1-enoyl-CoA to 2-oxo-6-hydroxycyclohex-1-enoyl-CoA and HF again via water addition to an fluorocyclohex-1-enoyl-CoA functionality. Formation of both 3-fluorocyclohexa-1,5-diene-1-carbonyl-CoA and 5-fluorocyclohexa-1,5-diene-1-carbonyl-CoA suggesting a low regioselectivity of benzoyl-coenzyme A (BzCoA) reductase (BCR) for fluorinated BzCoA analogues. Enzyme DCH and bifunctional 6-oxo-cyclohex-1-enoyl-CoA hydrolase (OAH) both initiate defluorination of the 2-fluorocyclohexa-1,5-diene-1-carbonyl-CoA intermediate by 1,4-hydration. Enzyme OAH is competent to hydrate both fluorinated cyclohexa-1,5-diene-carbonyl-CoA isomers and exhibits a similar reactivity as enzyme DCH, and OAH alone is capable of defluorinating both fluorinated cyclohexa-1,5-diene-carbonyl-CoA isomers formed by BCR. Detailed pathway overview |
-, 747850 |
