5.3.3.18	physiological function	mutants with a deletion of paaG gene are unable to grow on phenylacetate as carbon source. Incubation of a paaG mutant with [U-13C8]phenylacetate yields ring-1,2-dihydroxy-1,2-dihydrophenylacetyl lactone. The paaG mutant also converts phenylacetate into ortho-hydroxyphenylacetate, a dead end product of phenylacetate catabolism. The catabolic pathway of phenylacetate involves CoA thioesters. Phenylacetyl-CoA is attacked by a ring-oxygenase/reductase, PaaABCDE proteins, generating a hydroxylated and reduced derivative of phenylacetyl-CoA. The intermediate CoA ester is further metabolized in a complex reaction sequence comprising enoyl-CoA isomerization/hydration, nonoxygenolytic ring opening, and dehydrogenation catalyzed by the PaaG and PaaZ proteins	714891