Substrate-induced radical formation in 4-hydroxybutyryl coenzyme A dehydratase from Clostridium aminobutyricum.

ABSTRACT: 4-Hydroxybutyryl-coenzyme A (CoA) dehydratase (4HBD) from Clostridium aminobutyricum catalyzes the reversible dehydration of 4-hydroxybutyryl-CoA to crotonyl-CoA and the irreversible isomerization of vinylacetyl-CoA to crotonyl-CoA. 4HBD is an oxygen-sensitive homotetrameric enzyme with one [4Fe-4S](2+) cluster and one flavin adenine dinucleotide (FAD) in each subunit. Upon the addition of crotonyl-CoA or the analogues butyryl-CoA, acetyl-CoA, and CoA, UV-visible light and electron paramagnetic resonance (EPR) spectroscopy revealed an internal one-electron transfer to FAD and the [4Fe-4S](2+) cluster prior to hydration. We describe an active recombinant 4HBD and variants produced in Escherichia coli. The variants of the cluster ligands (H292C [histidine at position 292 is replaced by cyste

SUBMITTER: Zhang J 

PROVIDER: S-EPMC4292473 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature