Mutational analysis and homology modelling of SyrC, the aminoacyltransferase in the biosynthesis of syringomycin

Maria Rosaria Fullone; Alessandro Paiardini; Dennis C Gross; Shi-En Lu; Alberto Fiore; Ingeborg Grgurina

doi:10.1016/j.bbrc.2007.09.116

Mutational analysis and homology modelling of SyrC, the aminoacyltransferase in the biosynthesis of syringomycin

Biochem Biophys Res Commun. 2007 Dec 14;364(2):201-7. doi: 10.1016/j.bbrc.2007.09.116. Epub 2007 Oct 4.

Authors

Maria Rosaria Fullone¹, Alessandro Paiardini, Dennis C Gross, Shi-En Lu, Alberto Fiore, Ingeborg Grgurina

Affiliation

¹ Department of Biochemical Sciences A. Rossi Fanelli, University of Rome La Sapienza, P.le A. Moro, 5, 00185 Rome, Italy.

PMID: 17945189
DOI: 10.1016/j.bbrc.2007.09.116

Abstract

SyrC, a component of the multienzyme system of syringomycin biosynthesis, has been shown to shuttle Thr/4-Cl-Thr between the thiolation domains SyrB1-T1 and SyrE-T8,9 by transiently linking it to Cys224 in the enzyme active site. We present data on the structure-function relationship in vivo of this protein and an in silico model of its three-dimensional structure. The biosynthetic activity of SyrC was not influenced when either Asp348 or His376 that together with Cys224 form a putative catalytic triad, were replaced with Ala, but it was abolished by the exchange Cys224 with Ser. The presence of the FLAG peptide on either the N- or C-terminus of the protein did not affect activity, whereas the deletion of the first 16 amino acids at the N-terminus or the insertion of Maltose Binding Protein abolished the production of syringomycin. We present the model of the three-dimensional structure of SyrC suggesting a homodimeric structure for the protein and biochemical data that are supportive of this model.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Aminoacyltransferases / chemistry*
Aminoacyltransferases / genetics
Aminoacyltransferases / physiology
Bacterial Proteins / biosynthesis*
Bacterial Proteins / chemistry*
Bacterial Proteins / genetics
Bacterial Proteins / physiology
Carrier Proteins / genetics
Dimerization
Maltose-Binding Proteins
Models, Molecular*
Molecular Sequence Data
Mutagenesis, Site-Directed
Mutation
Oligopeptides
Peptide Synthases / chemistry*
Peptide Synthases / genetics
Peptide Synthases / physiology
Peptides / genetics
Protein Conformation
Pseudomonas syringae / genetics
Pseudomonas syringae / metabolism*
Recombinant Fusion Proteins / chemistry
Recombinant Fusion Proteins / genetics
Sequence Homology, Amino Acid
Structure-Activity Relationship

Substances

Bacterial Proteins
Carrier Proteins
Maltose-Binding Proteins
Oligopeptides
Peptides
Recombinant Fusion Proteins
syringomycin
FLAG peptide
Aminoacyltransferases
Peptide Synthases
SyrC protein, Pseudomonas syringae