PDBsum entry 4jn4

Chaperone

PDB id: 4jn4

Contents

Protein chains

600 a.a.

Ligands

ATP ×2

SO4 ×11

GOL ×4

Metals

_MG ×2

Waters ×1086

PDB id:

4jn4

Name:

Chaperone

Title:

Allosteric opening of the polypeptide-binding site when an hsp70 binds atp

Structure:

Chaperone protein dnak. Chain: a, b. Fragment: unp residues 2-610. Engineered: yes. Mutation: yes

Source:

Escherichia coli. Organism_taxid: 83333. Strain: k12. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.30Å R-factor: 0.164 R-free: 0.197

Authors:

R.Qi,E.B.Sarbeng,Q.Liu,K.Q.Le,X.Xu,H.Xu,J.Yang,J.L.Wong,C.Vorvis, W.A.Hendrickson,L.Zhou,Q.Liu

Key ref:

R.Qi et al. (2013). Allosteric opening of the polypeptide-binding site when an Hsp70 binds ATP. Nat Struct Biol, 20, 900-907. PubMed id: 23708608 DOI: 10.1038/nsmb.2583

Date:

14-Mar-13 Release date: 29-May-13

Protein chains

P0A6Y8  (DNAK_ECOLI) -  Chaperone protein DnaK from Escherichia coli (strain K12)

Seq: 638 a.a.

Struc: 600 a.a.*

* PDB and UniProt seqs differ at 5 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1038/nsmb.2583

Nat Struct Biol 20:900-907 (2013)

PubMed id: 23708608

Allosteric opening of the polypeptide-binding site when an Hsp70 binds ATP.

R.Qi, E.B.Sarbeng, Q.Liu, K.Q.Le, X.Xu, H.Xu, J.Yang, J.L.Wong, C.Vorvis, W.A.Hendrickson, L.Zhou, Q.Liu.

ABSTRACT

The 70-kilodalton (kDa) heat-shock proteins (Hsp70s) are ubiquitous molecular chaperones essential for cellular protein folding and proteostasis. Each Hsp70 has two functional domains: a nucleotide-binding domain (NBD), which binds and hydrolyzes ATP, and a substrate-binding domain (SBD), which binds extended polypeptides. NBD and SBD interact little when in the presence of ADP; however, ATP binding allosterically couples the polypeptide- and ATP-binding sites. ATP binding promotes polypeptide release; polypeptide rebinding stimulates ATP hydrolysis. This allosteric coupling is poorly understood. Here we present the crystal structure of an intact ATP-bound Hsp70 from Escherichia coli at 1.96-Å resolution. The ATP-bound NBD adopts a unique conformation, forming extensive interfaces with an SBD that has changed radically, having its α-helical lid displaced and the polypeptide-binding channel of its β-subdomain restructured. These conformational changes, together with our biochemical assays, provide a structural explanation for allosteric coupling in Hsp70 activity.