Generation of formate by the formyltransferase/hydrolase complex (Fhc) from Methylobacterium extorquens AM1.

Methylobacterium extorquens AM1 possesses a formyltransferase (Ftr) complex that is essential for growth in the presence of methanol and involved in formaldehyde oxidation to CO(2). One of the subunits of the complex carries the catalytic site for transfer of the formyl group from tetrahydromethanopterin to methanofuran (MFR). We now found via nuclear magnetic resonance-based studies that the Ftr complex also catalyzes the hydrolysis of formyl-MFR and generates formate. The enzyme was therefore renamed Ftr/hydrolase complex (Fhc). FhcA shares a sequence pattern with amidohydrolases and is assumed to be the catalytic site where the hydrolysis takes place.