Determinants for Substrate Recognition in the Glycyl Radical Enzyme Benzylsuccinate Synthase Revealed by Targeted Mutagenesis

Anaerobic toluene degradation is initiated by adding toluene to fumarate via the glycyl radical enzyme benzylsuccinate synthase (BSS). We developed a recombinant production system producing active BSS and present data on the effects of some active-site mutants. A single substitution of Ile617 to Val inside a hydrophobic pocket of the active site leads to an extended substrate range of the variant, which includes conversion of m-xylene, but not...