Ketosamine-3-kinase involved in protein deglycation by mediating phosphorylation of ribuloselysine and psicoselysine on glycated proteins, to generate ribuloselysine-3 phosphate and psicoselysine-3 phosphate, respectively (PubMed:14633848). Ribuloselysine-3 phosphate and psicoselysine-3 phosphate adducts are unstable and decompose under physiological conditions (PubMed:14633848). Not able to phosphorylate fructoselysine (PubMed:14633848). ATP + N(6)-D-ribulosyl-L-lysyl-[protein] = ADP + H(+) + N(6)-(3-O-phospho-D-ribulosyl)-L-lysyl-[protein] ATP + N(6)-(D-psicosyl)-L-lysyl-[protein] = ADP + H(+) + N(6)-(3-O-phospho-D-psicosyl)-L-lysyl-[protein] The ATP-binding domain is structurally related to aminoglycoside phosphotransferase family. Belongs to the fructosamine kinase family.