The ycj gene cluster from Escherichia coli K-12. The proteins encoded by this cluster include two polysaccharide hydrolases/phosphorylases (YcjM and YcjT), five sugar transporters (YcjN, YcjO, YcjP, YcjV, and OmpG, a porin), two NAD+-dependent dehydrogenases (YcjQ and YcjS), a putative isomerase/epimerase (YcjR), a β-phosphoglucomutase (YcjU), and a LacI-type repressor (YcjW).