Structural and biochemical research from the orf12 gene product or service (ORF12) from the clavulanic acid (CA) biosynthesis gene cluster are described. Sequence and crystallographic analyses reveal two domains: a C-terminal penicillin-binding protein (PBP)/beta-lactamase-type fold with further info highest structural similarity on the class A beta-lactamases selleck chem fused to an N-terminal domain that has a fold related to steroid isomerases and polyketide cyclases. The C-terminal domain of ORF12 didn't demonstrate beta-lactamase or PBP activity to the substrates examined, but did demonstrate low-level esterase activity in direction of 3'-O-acetyl cephalosporins plus a thioester substrate. Mutagenesis scientific studies imply that Ser173, which is current in the conserved SXXK motif, acts being a nucleophile in catalysis, constant with studies of connected esterases, beta-lactamases and d-Ala carboxypeptidases. Structures of wild-type ORF12 and of catalytic residue variants had been obtained in complex with and inside the absence of clavulanic acid. The function of ORF12 in clavulanic acid biosynthesis is Interleukin-11 receptor unknown, but it might be involved with the epimerization of (3S,5S)-clavaminic acid to (3R,5R)-clavulanic acid.