Component of the BbsAB thiolase complex, which catalyzes the thiolytic cleavage of (S)-2-benzoylsuccinyl-CoA to succinyl-CoA and benzoyl-CoA, the final step of anaerobic toluene metabolism. The BbsA subunit critically contributes to an induced-fit process for productive binding of a CoA substrate into the active site of BbsB