Comment | Two types of dihydroxyacetone kinase (glycerone kinase) are described. In yeast and a few bacteria, e.g. Citrobacter freundii, the enzyme is a single chain that uses ATP as phosphoryl donor and is designated EC 2.7.1.29. By contract, E. coli and many other bacterial species have a multisubunit form with a phosphoprotein donor related to PTS transport proteins. This family represents a protein, unique to the Firmicutes (low GC Gram-positives), that appears to be a divergent second copy of the K subunit of that complex; its gene is always found in operons with the other three proteins of the complex. |