Molecular genetic analysis of a locus required for resistance to antimicrobial peptides in Salmonella typhimurium.
AUTOR(ES)
Parra-Lopez, C
RESUMO
The innate immunity of vertebrates and invertebrates to microbial infection is mediated in part by small cationic peptides with antimicrobial activity. Successful pathogens have evolved mechanisms to withstand the antibiotic activity of these molecules. We have isolated a set of genes from Salmonella typhimurium which are required for virulence and resistance to the antimicrobial peptides melittin and protamine. Sequence analysis of a 5.7 kb segment from the wild-type plasmid conferring resistance to protamine contained five open reading frames: sapA, sapB, sapC, sapD and sapF, organized in an operon structure and transcribed as a 5.3 kb mRNA. SapD and SapF exhibited similarity with the 'ATP binding cassette' family of transporters including the bacterial Opp and SpoOK, involved in the uptake of oligopeptides; the yeast STE6, necessary for the export of a peptide pheromone; and the mammalian mdr, which mediates resistance to chemotherapeutic agents in cancer cells. SapA showed identity with other periplasmic solute binding proteins involved in peptide transport. The SapABCDF system constitutes a novel transporter for enteric bacteria and the first one harboring a periplasmic component with a role in virulence.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=413698Documentos Relacionados
- A Salmonella protein that is required for resistance to antimicrobial peptides and transport of potassium.
- apbA, a new genetic locus involved in thiamine biosynthesis in Salmonella typhimurium.
- Fine-structure genetic map of the cysB locus in Salmonella typhimurium.
- Genetic map of the opp (Oligopeptide permease) locus of Salmonella typhimurium.
- A locus affecting nucleoid segregation in Salmonella typhimurium.