Involved in the catabolism of oxalate and in the adapatation to low pH via the induction of the oxalate-dependent acid tolerance response (ATR). Essential enzyme for the bacterium survival, as it relies on oxalic acid as its sole source of energy. Catalyzes the transfer of the CoA moiety from formyl-CoA to oxalate (PubMed:15213226, PubMed:18162462, PubMed:18245280, PubMed:2361939, PubMed:9150242). It can also use succinate as acceptor (PubMed:18245280, PubMed:2361939). formyl-CoA + oxalate = formate + oxalyl-CoA formyl-CoA + succinate = formate + succinyl-CoA Inhibited by the sulfhydryl reagents N-ethylmaleimide and p-chloromercuribenzoate, and by chloride. Competitively inhibited by acetyl-CoA. kcat is 5.3 sec(-1) for CoA-transferase activity with formyl-CoA as substrate (with oxalate as acceptor at pH 6.7 and 30 degrees Celsius). kcat is 149 sec(-1) for CoA-transferase activity with formyl-CoA as substrate (with succinate as acceptor at pH 6.7 and 30 degrees Celsius). Optimum pH is between 6.5 and 7.5. Metabolic intermediate degradation; oxalate degradation; CO(2) and formate from oxalate: step 1/2. Homodimer. Belongs to the CoA-transferase III family. Frc subfamily.