DELVING INTO D-AMINO ACIDS

Abstract

EVER SINCE researchers discovered that the biological world makes use of L-amino acids to form proteins, mirror-image D-amino acids have mostly been relegated to the sidelines by biochemists. But new work is now adding weight to the idea that D-amino acids play vital roles in biological processes. Vibrio cholerae, the bacterium responsible for cholera, uses D-methionine and D-leucine as mortar to strengthen a layer of peptidoglycan that provides structural support to its cell walls, a team of researchers led by Matthew K. Waldor of Harvard Medical School reports in Science (2009, 325 , 1552). The team finds that these D-amino acids also regulate enzymes that build the peptidoglycan scaffolding. When the D-amino acids are present, construction slows to a stop. Use of D-amino acids is not just a quirk of V. cholerae . The team finds that Bacillus subtilis, an evolutionarily unrelated microbe, also uses the two D-amino acids. In fact, because the microbes also export ...