cd10170: HSP70_NBD (this model, PSSM-Id:212667 is obsolete and has been replaced by 466811)
Nucleotide-binding domain of the HSP70 family
HSP70 (70-kDa heat shock protein) family chaperones 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. HSP70 chaperone activity is regulated by various co-chaperones: J-domain proteins and nucleotide exchange factors (NEFs). Some HSP70 family members are not chaperones but instead, function as NEFs to remove ADP from their HSP70 chaperone partners during the ATP hydrolysis cycle, some may function as both chaperones and NEFs.