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*

*Corresponding author for this work

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

SyrC, a component of the multienzyme system of syringomycin biosynthesis, has been shown to shuttle Thr/4-Cl-Thr between the thiolation domains SyrBl-Tl and Syr-E-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.

Original languageEnglish
Pages (from-to)201-207
Number of pages7
JournalBiochemical and Biophysical Research Communications
Volume364
Issue number2
DOIs
Publication statusPublished - 14 Dec 2007
Externally publishedYes

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