Emerging knowledge of regulatory roles of d-amino acids in bacteria

• Published in: Cellular and molecular life sciences : CMLS 2011-03, Vol.68 (5), p.817-831
• Main Authors: Cava, Felipe, Lam, Hubert, de Pedro, Miguel A., Waldor, Matthew K.
• Format: Article
• Language: English
• Subjects: Aging; Amino Acid Isomerases - physiology; Amino acids; Amino Acids - biosynthesis; Amino Acids - chemistry; Amino Acids - physiology; Bacteria; Bacteria - metabolism; Bacterial proteins; Biochemistry; biofilm; Biofilms; Biomedical and Life Sciences; Biomedicine; Cell Biology; Cell Wall - metabolism; Cellular biology; D-amino acid; Enzymes; Life Sciences; Models, Biological; Molecular biology; peptidoglycan; Peptidoglycan - chemistry; racemase; regulation; Review; Spores, Bacterial - metabolism; stationary phase
• ISSN: 1420-682X; 1420-9071; 1420-9071
• DOI: 10.1007/s00018-010-0571-8

The d- enantiomers of amino acids have been thought to have relatively minor functions in biological processes. While l -amino acids clearly predominate in nature, d- amino acids are sometimes found in proteins that are not synthesized by ribosomes, and d- Ala and d- Glu are routinely found in the peptidoglycan cell wall of bacteria. Here, we review recent findings showing that d- amino acids have previously unappreciated regulatory roles in the bacterial kingdom. Many diverse bacterial phyla synthesize and release d- amino acids, including d- Met and d- Leu, which were not previously known to be made. These noncanonical d- amino acids regulate cell wall remodeling in stationary phase and cause biofilm dispersal in aging bacterial communities. Elucidating the mechanisms by which d- amino acids govern cell wall remodeling and biofilm disassembly will undoubtedly reveal new paradigms for understanding how extracytoplasmic processes are regulated as well as lead to development of novel therapeutics.