The phosphoenolpyruvate:mannose phosphotransferase system of Streptococcus salivarius. Functional and biochemical characterization of IIABLMan and IIABHMan

The phosphotransferase system proteins IIIHMan and IIILMan of Streptococcus salivarius were biochemically and functionally characterized through partial purification by gel filtration and ion-exchange chromatography and through separation by two-dimensional gel electrophoresis. The results showed that the two varieties of IIIMan have two phosphorylation sites, one of which is heat resistant, while the other is heat-labile. The phosphorylation on two histidine residues was confirmed through comparison of the N-terminal amino acid sequences with the N-terminal sequence of IIA domains of the mannose family.