|
type |
Journal Article |
authors |
Tai, C. H.; Cook, P. F. |
title |
Pyridoxal 5'-phosphate-dependent alpha,beta-elimination reactions: mechanism of O-acetylserine sulfhydrylase |
journal |
Acc Chem Res |
Activity |
2.5.1.47 |
ui |
21110263 |
year |
(2001) |
volume |
34 |
number |
1 |
pages |
49-59. |
| |
keywords |
Cysteine Synthase/*metabolism |
abstract |
O-Acetylserine sulfhydrylase catalyzes the replacement of the beta- acetoxy group of O-acetyl-L-serine with sulfide to generate L-cysteine. The reaction represents the final step in the biosynthesis of L- cysteine in enteric bacteria and plants. A quinonoid intermediate has not been detected using a variety of kinetic and spectroscopic probes for the wild-type or mutant enzymes, ruling out an E1 mechanism. The structure of the external Schiff base intermediate indicates an anti elimination. O-Acetylserine sulfhydrylase is the only known pyridoxal 5'-phosphate-dependent enzyme that catalyzes a beta-elimination reaction to have an anti E2 mechanism. |
last changed |
2003/03/17 14:53 |
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