nucleotide-binding domain (NBD) of the first repeat of hexokinase domain-containing protein 1 (HKDC1) from metazoan hexokinase (HK) domain family
Hexokinase (EC 2.7.1.1) possesses the ability to transfer an inorganic phosphate group from ATP to a substrate. It catalyzes the ATP-dependent phosphorylation of aldo- and keto-hexose sugars to the hexose-6-phosphate (H6P). It can catalyze this reaction on glucose, fructose, sorbitol and glucosamine, and as such is the first step in a number of metabolic pathways. Hexokinase contains two structurally similar domains. Some members of the family have two copies of each of these domains. For example, members from vertebrates contain four hexokinase isozymes, designated I to IV, where types I to III contain a duplication of the two-domain yeast-type hexokinases. HKDC1 is a putative novel fifth hexokinase found in vertebrates. It may be involved in whole-body glucose use. The model corresponds to the first two domains of HKDC1.
Feature 1:putative nucleotide binding site [chemical binding site]
Evidence:
Comment:Hexokinase I may reveal multiple ADP binding sites. One is located at the active site at the C-terminal half and the other locates to the N-terminal half at a site well removed from its active site.
Comment:Based on the structural evidence that Homo sapiens hexokinase I (1DGK) binds ADP at the N-terminal half
Jiyao W et al.(2023). "The conserved domain database in 2023.",