Gene organization of the operon and ulaA–G regulon involved in l-ascorbate metabolism
in E.
coli, which encodes a phosphotransferase system (PTS) (ulaABC genes). The putative functional analogues of the ula genes from M. synoviae 53, M. agalactiae PG2, and Listeria monocytogenes str. 4b are shown in the same colors. In red are the lactonases
from M. synoviae 53, M. agalactiae PG2, and L. monocytogenes str. 4b. The gene names
in order of M. synoviae 53 are ulaR/yjfq/rpiR transcriptional repressor for the l-ascorbate utilization ula divergon; Ms0025 hypothetical protein (phosphorylated
sugar lactonase); ulaA/sgaT PTS system ascorbate-specific
transporter subunit II, C component; sagB PTS system,
IIB component, pentitol phosphotransferase enzyme II, B component; sgaA pentitol phosphotransferase enzyme II, A component; ulaD/sgaH 3-keto-l-gulonate-6-phosphate
decarboxylase; ulaE/sgaUl-xylulose 5-phosphate 3-epimerase; ulaF/sagE/araDl-ribulose-5-phosphate
4-epimerase; MS53_0032, haloacid dehalogenase superfamily subclass
Iib sugar phosphatase.