Structural and Biochemical Characterization of Xylella fastidiosa DsbA Family Members: New Insights into the Enzyme-Substrate Interaction

Author(s)

Rinaldi, Fabio C. ^[1] ; Meza, Andreia N. ^[1] ; Guimaraes, Beatriz G. ^[1]

Affiliation

^[1] Brazilian Synchrotron Light Lab LNLS, Campinas, SP - Brazil

• Document type: Journal article
• Source: BIOCHEMISTRY; v. 48, n. 15, p. 3508-3518, 2009.
• Web of Science Citations: 14

Abstract

Disulfide oxidoreductase DsbA catalyzes disulfide bond formation in proteins secreted to the periplasm and has been related to the folding process of virulence factors in many organisms. It is among the most oxidizing of the thioredoxin-like proteins, and DsbA redox power is understood in terms of the electrostatic interactions involving the active site motif CPHC. The plant pathogen Xylella fastidiosa has two chromosomal genes encoding two oxidoreductases belonging to the DsbA family, and in one of them, the canonical motif CPHC is replaced by CPAC. Biochemical assays showed that both X. fastidiosa homologues have similar redox properties and the determination of the crystal structure of XfDsbA revealed substitutions in the active site of X. fastidiosa enzymes, which are proposed to compensate for the lack of the conserved histidine in XfDsbA2. In addition, electron density maps showed a ligand bound to the XfDsbA active site, allowing the characterization of the enzyme interaction with an 8-mer peptide. Finally, surface analysis of XfDsbA and XfDsbA2 suggests that X. fastidiosa enzymes may have different substrate specificities. (AU)

• FAPESP's process: 00/10266-8 - A structural biology laboratory network for the study of the 3D structures of proteins
• Grantee: Nilson Ivo Tonin Zanchin
• Support Opportunities: Genome Research Grants
• FAPESP's process: 98/14138-2 - Center for Structural Molecular Biotechnology
• Grantee: Glaucius Oliva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC