7ptj

Publication Abstract from PubMed

Choline-O-sulfatase (COSe; EC 3.1.6.6) is a member of the alkaline phosphatase (AP) superfamily, and its natural function is to hydrolyze choline-O-sulfate into choline and sulfate. Despite its natural function, the major interest in this enzyme resides in the landmark catalytic/substrate promiscuity of sulfatases, which has led to attention in the biotechnological field due to their potential in protein engineering. In this work, an in-depth structural analysis of wild-type Sinorhizobium (Ensifer) meliloti COSe (SmeCOSe) and its C54S active-site mutant is reported. The binding mode of this AP superfamily member to both products of the reaction (sulfate and choline) and to a substrate-like compound are shown for the first time. The structures further confirm the importance of the C-terminal extension of the enzyme in becoming part of the active site and participating in enzyme activity through dynamic intra-subunit and inter-subunit hydrogen bonds (Asn146(A)-Asp500(B)-Asn498(B)). These residues act as the `gatekeeper' responsible for the open/closed conformations of the enzyme, in addition to assisting in ligand binding through the rearrangement of Leu499 (with a movement of approximately 5 A). Trp129 and His145 clamp the quaternary ammonium moiety of choline and also connect the catalytic cleft to the C-terminus of an adjacent protomer. The structural information reported here contrasts with the proposed role of conformational dynamics in promoting the enzymatic catalytic proficiency of an enzyme.

Structural insights into choline-O-sulfatase reveal the molecular determinants for ligand binding.,Gavira JA, Camara-Artigas A, Neira JL, Torres de Pinedo JM, Sanchez P, Ortega E, Martinez-Rodriguez S Acta Crystallogr D Struct Biol. 2022 May 1;78(Pt 5):669-682. doi:, 10.1107/S2059798322003709. Epub 2022 Apr 26. PMID:35503214^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.