title: A conserved hydrolase responsible for the cleavage of aminoacylphosphatidylglycerol in the membrane of Enterococcus faecium.
abstract: Aminoacylphosphatidylglycerol synthases (aaPGSs) are enzymes that transfer amino acids from aminoacyl-tRNAs (aa-tRNAs) to phosphatidylglycerol (PG) to form aa-PG in the cytoplasmic membrane of bacteria. aa-PGs provide bacteria with resistance to a range of antimicrobial compounds and stress conditions. Enterococcus faecium encodes a triple-specific aaPGS (RakPGS) that utilizes arginine, alanine, and lysine as substrates. Here we identify a novel hydrolase (AhyD), encoded immediately adjacent to rakPGS in E. faecium, which is responsible for the hydrolysis of aa-PG. The genetic synteny of aaPGS and ahyD is conserved in >60 different bacterial species. Deletion of ahyD in E. faecium resulted in increased formation of Ala-PG and Lys-PG and increased sensitivity to bacitracin. Our results suggest that AhyD and RakPGS act together to maintain optimal levels of aa-PG in the bacterial membrane to confer resistance to certain antimicrobial compounds and stress conditions.
authors.affiliation: Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32826, USA.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Smith
authors.forename: Jesse S
authors.initials: JS
authors.lastname: Harrison
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Sprague
authors.forename: Hervé
authors.initials: H
authors.lastname: Roy
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D016984:Enterococcus faecium / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D006867:Hydrolases / Q000378:metabolism*; D006868:Hydrolysis; D010715:Phosphatidylglycerols / Q000378:metabolism*; D010802:Phylogeny
chemical_list: D001426:Bacterial Proteins; D010715:Phosphatidylglycerols; D006867:Hydrolases
keywords: Amino Acid; Aminoacyl tRNA Synthetase; Lipids; Membrane Proteins; Multiple Peptide Resistance Factor (MprF); Phosphatidylglycerol; Phospholipid; Transfer RNA (tRNA)