nucleotide-binding domain (NBD) of polyphosphate glucokinase (PPGK) and similar proteins
PPGK (EC 2.7.1.63/EC 2.7.1.2), also called poly(P)/ATP-glucomannokinase (GMK), poly(P) glucokinase, ATP-dependent glucokinase, or polyphosphate--glucose phosphotransferase, catalyzes the phosphorylation of glucose using polyphosphate or ATP as the phosphoryl donor. Polyphosphate, rather than ATP, seems to be the major phosphate donor for the enzyme in Mycobacterium tuberculosis. GTP, UTP and CTP can replace ATP as phosphoryl donor. PPGK belongs to the kinase (ROK) family, a group of proteins that have sugar kinase and/or transcriptional repressor activities. Members of this family lack the cysteine-rich zinc-binding motif, which presents in other ROK families.