ArcD1 and ArcD2 Arginine/Ornithine Exchangers Encoded in the Arginine Deiminase Pathway Gene Cluster of Lactococcus lactis

Abstract

The arginine deiminase (ADI) pathway gene cluster in Lactococcus lactis contains two copies of a gene encoding an l-arginine/l-ornithine exchanger, the arcD1 and arcD2 genes. The physiological function of ArcD1 and ArcD2 was studied by deleting the two genes. It is concluded that ArcD1 is the main l-arginine/l-ornithine exchanger in the ADI pathway. ArcD2 is proposed to function as a l-arginine/l-alanine exchanger in a pathway together with the arcT gene, which is found adjacent to the arcD2 gene in the ADI gene cluster.