L-Alanine is an essential component of both proteins and Peptidoglycan. Peptidoglycan also contain about three molecules of D-alanine for every L-alanine, comprising of only about 10% of the total alanine synthesized flowing into peptidoglycan. (More info can be found at L-alanine metabolism pathway: PW000788 or SMP0000810) In this pathway, D-amino acid dehydrogenase degrades D-alanine to form pyruvate, pyruvate then serving as a source of carbon for central metabolism. D-alanine can be formed by either biosynthetic alanine racemase or catabolic alanine racemase. D-alanine is required for forming cell wall peptidoglycan (murein). D-alanine is metabolized by ATP driven D-alanine ligase A and B resulting in D-alanyl-D-alanine. This product is incorporated into peptidoglycan biosynthesis.

D-Alanine Metabolism References