Title
Structural insights into choline-O-sulfatase reveal the molecular determinants for ligand binding
Author
Jose Antonio Gavira,a*‡ Ana Cámara-Artigas,b‡ Jose Luis Neira,c,d Jesús M. Torres de Pinedo,e Pilar Sánchez,e Esperanza Ortegae and Sergio Martinez-Rodrígueza,e*
Year
2022
Journal
Structural Biology
Abstract
In this work, we provide an in-depth structural analysis of SmeCOSe together with the first ligand-bound structures of this enzyme, providing clues to the molecular basis of its catalytic promiscuity. Our different ligand-bound structures confirm key roles of FGly54 (formyl-glycine), Asn75, Trp129, His145, His201 and Lys309 in ligand positioning, together with Asp386, which might also assist during product release. Contrary to the previous hypothesis, we confirm the general ligand-binding strategy observed for other choline-binding proteins, in which Trp129 and His145 belonging to a conserved β-hairpin are responsible for ligand accommodation. We further demonstrate the dynamic character of various residues in the catalytic environment as a result of ligand binding, including dynamic intra-subunit and inter-subunit hydrogen bonds (Asn146A–Asp500B–Asn498B) that are responsible for the open/closed conformations of the enzyme, while assisting in ligand binding through the rearrangement of Leu499, with a displacement of approximately 5 Å. Finally, based on information derived from our structures, we argue against the proposed role of conformational dynamics in promoting the enzymatic catalytic proficiency of SmeCOSe.
Instrument
J-815
Keywords
structure analysis, ligand, enzyme,