Role of Hsp70 ATPase Domain Intrinsic Dynamics and Sequence Evolution in Enabling its Functional Interactions with NEFs
(a) ATPase domain structure colored by subdomains: IA (red; residues 1–39 and 116–188), IB (blue; residues 40–115), IIA (green; residues 189–228 and 307-C-terminus) and IIB (orange; residues 229–306). Several subdomain IIB residues are involved in NEF recognition and binding, including residues at the C-terminal part of helix 8 (G230-H249), the helix 9 (K257-S275), and the β-sheet E (strands Q279-I284 and F293-T298 connected by a long exposed loop). Residue identifications and secondary structure nomenclature are based on the PDB entry 1HPM. In yellow stick representation is a bound ADP. (b–e) Interactions with four different NEFs. (b) DnaK ATPase fragment from E. coli complexed with GrpE, (c) bovine Hsc70 complexed with BAG-1, (d) human Hsc70 with Sse1, and (e) human Hsc70 with HspBP1. In each case the NEF is colored cyan, ATPase fragment white, and interface residues, shown in space-filling representation, are colored according to their subdomain locations. See Table S1 and Table S2, and the Materials and Methods for more information on the examined complexes, and the identity of NEF-recognition residues in each case. All ribbon diagrams are created using PyMol (http://www.pymol.org).