Download MendeleyStructural insights into choline-O-sulfatase reveal the molecular determinants for ligand binding.
Gavira, J.A., Camara-Artigas, A., Neira, J.L., Torres de Pinedo, J.M., Sanchez, P., Ortega, E., Martinez-Rodriguez, S.(2022) Acta Crystallogr D Struct Biol 78: 669-682
- PubMed: 35503214
- DOI: https://doi.org/10.1107/S2059798322003709
- Primary Citation of Related Structures:
6G5Z, 6G60, 7PTH, 7PTJ - PubMed Abstract:
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 Å). 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.
Organizational Affiliation:
Laboratorio de Estudios Cristalográficos, CSIC, Armilla, 18100 Granada, Spain.
