title: Serine hydroxymethyltransferase from the cold adapted microorganism Psychromonas ingrahamii: a low temperature active enzyme with broad substrate specificity.
abstract: Serine hydroxymethyltransferase from the psychrophilic microorganism Psychromonas ingrahamii was expressed in Escherichia coli and purified as a His-tag fusion protein. The enzyme was characterized with respect to its spectroscopic, catalytic, and thermodynamic properties. The properties of the psychrophilic enzyme have been contrasted with the characteristics of the homologous counterpart from E. coli, which has been structurally and functionally characterized in depth and with which it shares 75% sequence identity. Spectroscopic measures confirmed that the psychrophilic enzyme displays structural properties almost identical to those of the mesophilic counterpart. At variance, the P. ingrahamii enzyme showed decreased thermostability and high specific activity at low temperature, both of which are typical features of cold adapted enzymes. Furthermore, it was a more efficient biocatalyst compared to E. coli serine hydroxymethyltransferase (SHMT) particularly for side reactions. Many β-hydroxy-α-amino acids are SHMT substrates and represent important compounds in the synthesis of pharmaceuticals, agrochemicals and food additives. Thanks to these attractive properties, this enzyme could have a significant potential for biotechnological applications.
authors.affiliation: Department of Biochemical Sciences "A. Rossi Fanelli", University of Rome "La Sapienza", P.le Aldo Moro 5, Roma 00185, Italy.
authors.forename: Sebastiana
authors.initials: S
authors.lastname: Angelaccio
authors.affiliation: Department of Biochemical Sciences "A. Rossi Fanelli", University of Rome "La Sapienza", P.le Aldo Moro 5, Roma 00185, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Florio
authors.affiliation: Department of Biochemical Sciences "A. Rossi Fanelli", University of Rome "La Sapienza", P.le Aldo Moro 5, Roma 00185, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Consalvi
authors.affiliation: Department of Biochemical Sciences "A. Rossi Fanelli", University of Rome "La Sapienza", P.le Aldo Moro 5, Roma 00185, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Festa
authors.affiliation: Department of Biochemical Sciences "A. Rossi Fanelli", University of Rome "La Sapienza", P.le Aldo Moro 5, Roma 00185, Italy.
authors.forename: Stefano
authors.identifier: 0000-0002-6822-4022
authors.initials: S
authors.lastname: Pascarella
mesh_terms: D000220:Adaptation, Biological; D003080:Cold Temperature; D004795:Enzyme Stability; D020563:Gammaproteobacteria / Q000201:enzymology* / Q000235:genetics; D012696:Glycine Hydroxymethyltransferase / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification
chemical_list: D011994:Recombinant Proteins; D012696:Glycine Hydroxymethyltransferase