Biochemical similarities and differences between the catalytic [4Fe-4S] cluster containing fumarases FumA and FumB from Escherichia coli.

ABSTRACT:

Background

The highly homologous [4Fe-4S] containing fumarases FumA and FumB, sharing 90% amino acid sequence identity, from Escherichia coli are differentially regulated, which suggests a difference in their physiological function. The ratio of FumB over FumA expression levels increases by one to two orders of magnitude upon change from aerobic to anaerobic growth conditions.

Methodology/principal findings

To understand this difference in terms of structure-function relations, catalytic and thermodynamic properties were determined for the two enzymes obtained from homologous overexpression systems. FumA and FumB are essentially identical in their Michaelis-Menten kinetics of the reversible fumarate to L-malate conversion; however, FumB has a significantly greater catalytic

SUBMITTER: van Vugt-Lussenburg BM 

PROVIDER: S-EPMC3565967 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature