Representation of proteins does not account for molecular weight or oligomeric structure. There is no experimental data available for genes indicated in red. Colors of proteins are coordinated with the protein classification found in the COG database. For example, all 'C domains' of the fructose permeases (including putative ones) belong to COG1299 namely 'Phosphotransferase system, fructose-specific IIC component'.
The 'A domain' of the phosphoprotein encoded by ycgC is classified as uncharacterized in the COG database [COG3412]. However by using 3-D template matching Gutknecht et al. showed the 'A domain' to be affiliated to the mannose-specific IIA component [EMBO J].
CmtB (encoded by cmtB) and the IIA domain of Enzyme IICBAMtl (encoded by mtlA) are structurally similar overall however local structural differences exist in the active site [Biochem Biophys Res Commun].
The frvR gene encodes a two-domain protein. The amino-terminal domain (indicated as R) belongs to COG3711 typified by BglG. BglG is a cytoplasmic response regulator whose function, as a transcriptional antiterminator, is regulated by BglF-mediated reversible phosphorylation [Proc Natl Acad Sci U S A] [Proc Natl Acad Sci U S A] [Proc Natl Acad Sci U S A]. The domain composition of FrvR is reminiscent of the one described for the regulator LicR from Bacillus subtilis [J Bacteriol]. Translocation of PTS sugars by BglF has been studied in detail [J Bacteriol].
Enzyme IIA encoded by ptsN is involved in amino acids biosynthesis [Mol Microbiol]. It possibly interacts with TrkA which participates in potassium transport [Proc Natl Acad Sci U S A] and most likely with potassium sensor kinase KdpD [Mol Microbiol]. It is found readily phosphorylated in vivo [FEMS Microbiol Lett]. Regulatory roles for ptsN-, ptsO- and ptsP-encoded proteins were described and comparatively analyzed in a 2010 review [Trends Microbiol]. In 2011 the role of ptsN-encoded EIIANtr in regulating nitrogen source utilization, as previously proposed, was discarded [J Bacteriol]. In fact E. coli EIIANtr alters the response to phosphate starvation by binding histidine kinase PhoR [Mol Microbiol].
Another cryptic operon for utilization of β-glucosides was discovered in septicemic and uropathogenic E. coli [Appl Environ Microbiol].
Growth efficiency on N-acetylglucosamine as sole carbon source is related to various factors [J Bacteriol].
Escherichia coli K12 is unable to grow on galactosamine or N-acetylgalactosamine due to a deletion within the aga genes causing loss of the corresponding IIA domain [Mol Microbiol]. However the ability to grow on galactosamine or N-acetylgalactosamine differs among enteric bacteria. Strains of enterohemorrhagic Escherichia coli O157:H7 isolated from produce-associated outbreaks have lost the capability to grow on N-acetylgalactosamine [J Bacteriol].
Chromosomal location of the gat operon is not conserved among Enterobacteriaceae [Mol Genet Genomics].
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