nucleotide-binding domain (NBD) of Escherichia coli chaperone protein YegD and similar proteins
The family includes a group of uncharacterized proteins similar to Escherichia coli chaperone protein YegD that belongs to the heat shock protein 70 family of chaperones that assist in protein folding and assembly and can direct incompetent "client" proteins towards degradation. Typically, HSP70s have a nucleotide-binding domain (NBD) and a substrate-binding domain (SBD). The nucleotide sits in a deep cleft formed between the two lobes of the NBD. The two subdomains of each lobe change conformation between ATP-bound, ADP-bound, and nucleotide-free states. ATP binding opens up the substrate-binding site; substrate-binding increases the rate of ATP hydrolysis. YegD lacks the SBD. HSP70 chaperone activity is regulated by various co-chaperones: J-domain proteins and nucleotide exchange factors (NEFs). Some family members are not chaperones but instead, function as NEFs for their Hsp70 partners, other family members function as both chaperones and NEFs.
Jiyao W et al.(2023). "The conserved domain database in 2023.",