FIG 1.
Amino sugar utilization in E. coli. Protein-protein interactions of HPr-NagB, U-PII-NagB, and NanE-NagB activate NagB by increasing the affinity of the enzyme for its substrate, GlcN-6P, and/or increasing the Vmax. NagB, glucosamine 6-phosphate deaminase. These proteins are indicated by white rectangles adjacent to the upward-pointing arrows. NagA, N-acetylglucosamine 6-phosphate deacetylase; NANA, N-acetyl-d-neuraminic acid; NanA, NANA aldolase/lyase; PTS, phosphotransferase system; ManXYZ, the mannose PTS transport/kinase system; NanT, the NANA transporter; NanK, ManNAc kinase; GS, glutamine synthetase; PII (GlnB), nitrogen regulator; GlnD, uridylyltransferase/uridylylase for the PII protein; GlnE, adenylyltransferase/adenylylase.