Identification of Genetic Determinants and Enzymes Involved with the Amidation of Glutamic Acid Residues in the Peptidoglycan of Staphylococcus aureus

PLoS Pathogens

Alexander Tomasz¹  Ana Madalena Ludovice²  Waldemar Vollmer²  Hermínia de Lencastre³  Nhat K. Bui³  Rita G. Sobral⁴  João Manuel Feio de Almeida⁴  Teresa A. Figueiredo⁴ 

[1] Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom;Centro de Recursos Microbiológicos (CREM), Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, Caparica, Portugal;Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, Caparica, Portugal;Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Oeiras, Portugal

关键词: Peptidoglycans;    Amidation;    Staphylococcus aureus;    Cell walls;    Operons;    Sequence alignment;    Protein domains;    Reversed-phase high performance liquid chromatography;   

DOI  :  10.1371/journal.ppat.1002508

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The glutamic acid residues of the peptidoglycan of Staphylococcus aureus and many other bacteria become amidated by an as yet unknown mechanism. In this communication we describe the identification, in the genome of S. aureus strain COL, of two co-transcribed genes, murT and gatD, which are responsible for peptidoglycan amidation. MurT and GatD have sequence similarity to substrate-binding domains in Mur ligases (MurT) and to the catalytic domain in CobB/CobQ-like glutamine amidotransferases (GatD). The amidation of glutamate residues in the stem peptide of S. aureus peptidoglycan takes place in a later step than the cytoplasmic phase – presumably the lipid phase - of the biosynthesis of the S. aureus cell wall precursor. Inhibition of amidation caused reduced growth rate, reduced resistance to beta-lactam antibiotics and increased sensitivity to lysozyme which inhibited culture growth and caused degradation of the peptidoglycan.

【 授权许可】

CC BY