Minst.org › Ecach › Chapter I › Color-coded PTS

Representation of proteins does not account for their 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 and coworkers showed this "A domain" is affiliated to the mannose-specific IIA component [The EMBO Journal].

CmtB (encoded by cmtB) and the IIA domain of Enzyme IICBA^mtl (encoded by mtlA) are structurally similar overall however local structural differences exist in the active site [BBRC].

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 [PNAS] [PNAS].  The domain composition of FrvR is reminiscent of the one described for the regulator LicR from Bacillus subtilis [JB].  Translocation of PTS sugars by BglF has been studied in detail [JB].

Enzyme IIA encoded by ptsN is involved in amino acids biosynthesis [Molecular Microbiology].  It possibly interacts with TrkA which participates in potassium transport [PNAS] and most likely with potassium sensor kinase KdpD [Molecular Microbiology].  It is found readily phosphorylated in vivo [FEMS Microbiology Letters].  Regulatory roles for ptsN-, ptsO- and ptsP-encoded proteins were described and comparatively analyzed in a 2010 review [TIMI].

Another cryptic operon for utilization of β-glucosides was discovered in septicemic and uropathogenic E. coli [AEM].

Growth efficiency on N-acetylglucosamine as sole carbon source is related to various factors [JB].

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 [Molecular Microbiology].  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 [JB].

Chromosomal location of the gat operon is not conserved among Enterobacteriaceae [MGG].