Deciphering the specific interaction between the acyl carrier protein IacP and the T3SS‐major hydrophobic translocator SipB from Salmonella

• Published in: FEBS letters
• Main Authors: Canestrari, Mickaël J, Serrano, Bastien, Bartoli, Julia, Prima, Valerie, Bornet, Olivier, Puppo, Rémy, Bouveret, Emmanuelle, Guerlesquin, Francoise, Viala, Julie
• Format: Journal Article
• Language: English
• Published: Wiley 21.09.2019
• Series: Epub ahead of print
• Subjects: Bacteriology; Life Sciences; Microbiology and Parasitology; Salmonella; type 3 secretion system; IacP; Salmonella Typhimurium; Shigella flexneri; SPI 1; Pseudomonas fluorescens; translocator; acylation; stm; ACP; pfe; SipB; acyl carrier protein; translocon; 4¢-PP; heteronuclear single quantum coherence; sfl; T3SS; protein-protein interaction; Salmonella pathogenicity island 1; HSQC; 4¢-phosphopantetheine; ACP Abbreviations used: SPI-1
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1002/1873-3468.13593

Salmonella is a facultative intracellular pathogen that invades epithelial cells of the intestine using the SPI-1 Type 3 secretion System (T3SS). Insertion of the SPI-1 T3SS translocon is facilitated by acylation of the translocator SipB, which involves a protein-protein interaction with the acyl carrier protein IacP. Using nuclear magnetic resonance and biological tests, we identified the residues of IacP that are involved in the interaction with SipB. Our results suggest that the 4'-phosphopantetheine group that functionalizes IacP participates in the interaction. Its solvent exposition may rely on two residues highly conserved in acyl carrier proteins associated with T3SS. This study is the first to address the specificity of acyl carrier proteins associated with T3SS.