Affiliation:
1. Department of Microbiology, University of Colorado Medical Center, Denver, Colorado 80220
Abstract
Several diaminopimelic acid (DAP)- and lysine-requiring mutants of
Escherichia coli
were isolated and studied by genetic, physiological, and biochemical means. The genes concerned with DAP-lysine synthesis map at several different sites on the
E. coli
chromosome and, therefore, do not constitute a single operon. Three separate loci affecting DAP synthesis are located in the 0 to 2.5 min region of the genetic map. The order of the loci in this region is
thr-dapB-pyrA-ara-leu-pan-dapC-tonA-dapD
. Two additional DAP genes map in the region between min 47 and 48, with the gene order being
gua-dapA-dapE-ctr
. The
lys
locus at min 55 determines the synthesis of the enzyme DAP decarboxylase, which catalyzes the conversion of DAP into lysine. The order of the genes in this region is
serA-lysA-thyA
.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology