Structural and biochemical scientific studies of your orf12 gene products (ORF12) through 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 CXCR inhibitor FDA highest structural similarity on the class A beta-lactamases Interleukin-11 receptor fused to an N-terminal domain by using a fold related to steroid isomerases and polyketide cyclases. The C-terminal domain of ORF12 did not display beta-lactamase or PBP action for that substrates examined, but did demonstrate low-level esterase exercise towards 3'-O-acetyl cephalosporins plus a thioester substrate. Mutagenesis research imply that Ser173, which is existing in the conserved SXXK motif, acts as a nucleophile in catalysis, steady with scientific studies of related esterases, beta-lactamases and d-Ala carboxypeptidases. Structures of wild-type ORF12 and of catalytic residue variants were obtained in complicated with and during the absence of clavulanic acid. The position of ORF12 in clavulanic acid biosynthesis is http://www.selleckchem.com/GABA-transporter.html unknown, however it may perhaps be associated with the epimerization of (3S,5S)-clavaminic acid to (3R,5R)-clavulanic acid.