Fructoselysine kinase-like. Fructoselysine is a fructoseamine formed by glycation, a non-enzymatic reaction of glucose with a primary amine followed by an Amadori rearrangement, resulting in a protein that is modified at the amino terminus and at the lysine side chains. Fructoseamines are typically metabolized by fructoseamine-3-kinase, especially in higher eukaryotes. In E. coli, fructoselysine kinase has been shown in vitro to catalyze the phosphorylation of fructoselysine. It is proposed that fructoselysine is released from glycated proteins during human digestion and is partly metabolized by bacteria in the hind gut using a protein such as fructoselysine kinase. This family is found only in bacterial sequences, and its oligomeric state is currently unknown.