title: A Native Ternary Complex Trapped in a Crystal Reveals the Catalytic Mechanism of a Retaining Glycosyltransferase.
abstract: Glycosyltransferases (GTs) comprise a prominent family of enzymes that play critical roles in a variety of cellular processes, including cell signaling, cell development, and host-pathogen interactions. Glycosyl transfer can proceed with either inversion or retention of the anomeric configuration with respect to the reaction substrates and products. The elucidation of the catalytic mechanism of retaining GTs remains a major challenge. A native ternary complex of a GT in a productive mode for catalysis is reported, that of the retaining glucosyl-3-phosphoglycerate synthase GpgS from M. tuberculosis in the presence of the sugar donor UDP-Glc, the acceptor substrate phosphoglycerate, and the divalent cation cofactor. Through a combination of structural, chemical, enzymatic, molecular dynamics, and quantum-mechanics/molecular-mechanics (QM/MM) calculations, the catalytic mechanism was unraveled, thereby providing a strong experimental support for a front-side substrate-assisted SN i-type reaction.
authors.affiliation: Unidad de Biofísica, Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia (Spain).|IKERBASQUE, 48013 Bilbao (Spain).
authors.forename: David
authors.initials: D
authors.lastname: Albesa-Jové
authors.affiliation: IBB and Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra (Spain).
authors.forename: Fernanda
authors.initials: F
authors.lastname: Mendoza
authors.affiliation: Unidad de Biofísica, Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia (Spain).
authors.forename: Ane
authors.initials: A
authors.lastname: Rodrigo-Unzueta
authors.affiliation: Laboratorio de Síntesis Asimétrica, Departamento de Síntesis y Estructura de Biomoléculas, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza, CSIC, 50009 Zaragoza, Aragón (Spain).
authors.forename: Fernando
authors.initials: F
authors.lastname: Gomollón-Bel
authors.affiliation: Unidad de Biofísica, Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia (Spain).
authors.forename: Javier O
authors.initials: JO
authors.lastname: Cifuente
authors.affiliation: Unidad de Biofísica, Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia (Spain).
authors.forename: Saioa
authors.initials: S
authors.lastname: Urresti
authors.affiliation: Unidad de Biofísica, Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia (Spain).
authors.forename: Natalia
authors.initials: N
authors.lastname: Comino
authors.affiliation: IBB and Joint BSC-CRG-IRB Program in Computational Biology, IRB Barcelona, 08028 Barcelona (Spain).
authors.forename: Hansel
authors.initials: H
authors.lastname: Gómez
authors.affiliation: Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, 08017 Barcelona (Spain).
authors.forename: Javier
authors.initials: J
authors.lastname: Romero-García
authors.affiliation: IBB and Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra (Spain).
authors.forename: José M
authors.initials: JM
authors.lastname: Lluch
authors.affiliation: Unidad de Biofísica, Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia (Spain).
authors.forename: Enea
authors.initials: E
authors.lastname: Sancho-Vaello
authors.affiliation: Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, 08017 Barcelona (Spain).
authors.forename: Xevi
authors.initials: X
authors.lastname: Biarnés
authors.affiliation: Laboratory of Biochemistry, Institut Químic de Sarrià, Universitat Ramon Llull, 08017 Barcelona (Spain).
authors.forename: Antoni
authors.initials: A
authors.lastname: Planas
authors.affiliation: Laboratorio de Síntesis Asimétrica, Departamento de Síntesis y Estructura de Biomoléculas, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza, CSIC, 50009 Zaragoza, Aragón (Spain).
authors.forename: Pedro
authors.initials: P
authors.lastname: Merino
authors.affiliation: Institut de Biotecnologia i de Biomedicina (IBB) (Spain).
authors.forename: Laura
authors.initials: L
authors.lastname: Masgrau
authors.affiliation: Unidad de Biofísica, Consejo Superior de Investigaciones Científicas - Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC-UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48940 Leioa, Bizkaia (Spain). mrcguerin@gmail.com.|IKERBASQUE, 48013 Bilbao (Spain). mrcguerin@gmail.com.
authors.forename: Marcelo E
authors.initials: ME
authors.lastname: Guerin
mesh_terms: D055162:Biocatalysis; D018360:Crystallography, X-Ray; D016695:Glycosyltransferases / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D011789:Quantum Theory
chemical_list: D016695:Glycosyltransferases
keywords: enzyme catalysis; enzymes; glycosyltransferases; reaction mechanisms; structure elucidation