RT Journal Article SR Electronic(1) A1 WORK, ELIZABETHYR 1970 T1 The distribution of diamino acids in cell walls and its significance in bacterial taxonomy JF International Journal of Systematic and Evolutionary Microbiology, VO 20 IS 4 SP 425 OP 433 DO https://doi.org/10.1099/00207713-20-4-425 PB Microbiology Society, SN 1466-5034, AB ABSTRACT The distribution of diamino acids in cell walls of bacterial species bears some relation to taxonomy. The most widely distributed diamino acid is meso-diaminopimelic acid which is present in probably all Gram-negative species and in numerous other genera. L-lysine, also fairly common, is present in most Gram-positive cocci and in certain other species. Less frequent are DD or LL-diaminopimelic, β-OH - diaminopimelic, D or L ornithine, D or L diaminobutyric. The positions of these bifunctional amino acids in mucopep-tides (glycopeptides), the cross linked polymers of the walls, are described. Mucopeptides are divided into two types according to the site of termination of the cross-link from the D-alanine of an adjacent peptide chain. In type D, the site is the diamino acid which is located in the main peptide chain; in type G (less common) the site is the D-glutamic acid, and the diamino acid is in the cross link. Other differentiating features of types D and G include the optical configuration of the diamino acid, and the nature of the amino acid linking the peptide chain to the hexosamine backbone., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-20-4-425