TABLE 2.

Summary of names, substrates and functions of all enzymes used in this study

Name in this study	ORFa Prior name	Predicted function	Observed function	Substrate	Product
Strain 81–176 for 6-deoxy-d-altro-heptose pathway
DdahA	Cjj1426	C4, C6 dehydratase	C4, C6 dehydratase	GDP-manno-heptose	GDP-6-deoxy-4-keto-d-lyxo-heptose
DdahB	Cjj1430	C3, C5 epimerase/C4 reductase	C3 epimerase	GDP-6-deoxy-4-keto-d-lyxo-heptose	GDP-6-deoxy-4-keto-d-arabino heptose
DdahC	Cjj1427	C3, C5 epimerase/C4 reductase	C4 reductase	GDP-6-deoxy-4-keto-d-arabino heptose	GDP-6-deoxy-4-keto-d-altro heptose
WcaG81176	Cjj1425 WcaG	C4 reductase	C4 reductase	GDP-6-deoxy-4-keto-d-lyxo-heptose	GDP-6-deoxy-d-manno-heptose
Strain NCTC 11168 for 6-OMe-l-gluco-heptose pathwayb
MlghA	X	C4 oxidase	Not identified	GDP-manno-heptose	GDP-4-keto-d-lyxo-heptose
MlghD	Cj1426	6-O Methyl Transferase	Not determined	GDP-4-keto-d-lyxo-heptose	GDP-6-OMe-4-keto-d-lyxo-heptose
MlghB	Cj1430	C3, C5 epimerase/C4 reductase	C3, C5 epimerase	GDP-6-OMe-4-keto-d-lyxo-heptose	GDP-6-OMe-4-keto-l-xylo-he ptose
MlghC	Cj1428	C3, C5 epimerase/C4 reductase	C4 reductase	GDP-6-OMe-4-keto-l-xylo-heptose	GDP-6-OMe-4-keto-l-gluco-heptose
WcaGNCTC	Cj1427	C4 reductase	C4 reductase	GDP-6-OMe-4-keto-d-lyxo-heptose	GDP-6-OMe-d-manno-heptose

^a The ORFs and names were as indicated in the genome databases (see Ref. 26) for strain NCTC 11168 and www.ncbi.nlm.nih.gov for strain 81-176. Former names were as previously used in Refs. 24 and 25.

^b The enzymes are listed in the anticipated order of participation in the pathway. The assignment of the methyltransferase in the early steps of the pathway after the oxidation step is likely but speculative and awaits biochemical confirmation. Based on this assignment, the natural substrates for MlghB, MlghC, and WcaG_NCTC are anticipated to be 6-OMe-4-keto derivatives. The 6-deoxy-4-keto derivatives used as substrates in this study are surrogate substrates obtained by the initial activity of DdahA.