D-amino acids govern stationary phase cell wall remodeling in bacteria.
In all known organisms, amino acids are predominantly thought to be synthesized and used as their L-enantiomers. Here, we found that bacteria produce diverse D-amino acids as well, which accumulate at millimolar concentrations in supernatants of stationary phase cultures. In Vibrio cholerae, a dedicated racemase produced D-Met and D-Leu, whereas Bacillus subtilis generated D-Tyr and D-Phe. These unusual D-amino acids appear to modulate synthesis of peptidoglycan, a strong and elastic polymer that serves as the stress-bearing component of the bacterial cell wall. D-Amino acids influenced peptidoglycan composition, amount, and strength, both by means of their incorporation into the polymer and by regulating enzymes that synthesize and modify it. Thus, synthesis of D-amino acids may be a common strategy for bacteria to adapt to changing environmental conditions.
Lam
Hubert
H
Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, and Howard Hughes Medical Institute, Boston, MA 02115, USA.
Oh
Dong-Chan
DC
Cava
Felipe
F
Takacs
Constantin N
CN
Clardy
Jon
J
de Pedro
Miguel A
MA
Waldor
Matthew K
MK
D000409:Alanine / Q000737:chemistry / Q000378:metabolism; D000591:Amino Acid Isomerases / Q000235:genetics / Q000378:metabolism; D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism*; D001412:Bacillus subtilis / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D002473:Cell Wall / Q000378:metabolism* / Q000648:ultrastructure; D015536:Down-Regulation; D018698:Glutamic Acid / Q000737:chemistry / Q000378:metabolism; D007532:Isoleucine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry; D010457:Peptidoglycan / Q000096:biosynthesis* / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D013237:Stereoisomerism; D014633:Valine / Q000378:metabolism; D014734:Vibrio cholerae / Q000166:cytology / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure
D000596:Amino Acids; D009842:Oligopeptides; D010457:Peptidoglycan; D011134:Polysaccharides; D007532:Isoleucine; D018698:Glutamic Acid; D008715:Methionine; D000591:Amino Acid Isomerases; D007930:Leucine; D014633:Valine; D000409:Alanine