Physical organization of the dpkA/amaC genes and the ORFs encoding the PP3592 to PP3597 clusters involved in d-lysine catabolism. (A) Map of the two operons involved in the early steps of d-lysine catabolism. (B) RT-PCR to probe the operon structure of dpkA-amaC and ORF PP3592 through ORF PP3597. Primers used were designed based on the 3′ end of the upstream gene and the 5′ end of the downstream gene. Primer sequences are available on request. Lane 1′, RT-PCR based on dpkA-amaC primers; lane 2′, RT-PCR based on amaC and ORF PP3589 primers; lane 1, RT-PCR based on ORF PP3592 and ORF PP3593 primers; lane 2, RT-PCR based on ORF PP3593 and ORF PP3594 primers; lane 3, RT-PCR based on ORF PP3594 and ORF PP3595 primers; lane 4, RT-PCR based on ORF PP3595 and ORF PP3596 primers; lane 5, RT-PCR based on ORF 3596 and ORF PP3597 primers; lane 6, RT-PCR based on ORF PP3597 and ORF PP3598 primers; lane M, size markers.