 IIGut of "Escherichia coli" consists of three proteins, a IIA protein, a putative 4 TMS IIC2 protein and a putative 4 TMS IIC1 protein.The N- and C-termini as well as the IIB domain may thereby be localized to the cell cytoplasm, but the topology has not been established experimentally.IIAGut is believed to be phosphorylated on a histidyl residue, while IIBGut is probably phosphorylated on a cysteyl residue.