PDBsum entry 5e85

Chaperone

PDB id: 5e85

Contents

Protein chain

235 a.a.

Ligands

SO4

Waters ×48

PDB id:

5e85

Name:

Chaperone

Title:

Isolated sbd of bip

Structure:

78 kda glucose-regulated protein. Chain: a. Fragment: unp residues 418-637. Synonym: grp-78,endoplasmic reticulum lumenal ca(2+)-binding protein grp78,heat shock 70 kda protein 5,immunoglobulin heavy chain-binding protein,bip. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: hspa5, grp78. Expressed in: escherichia coli. Expression_system_taxid: 511693.

Resolution:

2.57Å R-factor: 0.222 R-free: 0.264

Authors:

Q.Liu,J.Yang,M.Nune,Y.Zong,L.Zhou

Key ref:

J.Yang et al. (2015). Close and Allosteric Opening of the Polypeptide-Binding Site in a Human Hsp70 Chaperone BiP. Structure, 23, 2191-2203. PubMed id: 26655470 DOI: 10.1016/j.str.2015.10.012

Date:

13-Oct-15 Release date: 30-Dec-15

Protein chain

P11021  (BIP_HUMAN) -  Endoplasmic reticulum chaperone BiP from Homo sapiens

Seq: 654 a.a.

Struc: 235 a.a.*

* PDB and UniProt seqs differ at 14 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.6.4.10 - non-chaperonin molecular chaperone ATPase.
• Reaction: ATP + H2O = ADP + phosphate + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1016/j.str.2015.10.012

Structure 23:2191-2203 (2015)

PubMed id: 26655470

Close and Allosteric Opening of the Polypeptide-Binding Site in a Human Hsp70 Chaperone BiP.

J.Yang, M.Nune, Y.Zong, L.Zhou, Q.Liu.

ABSTRACT

Binding immunoglobulin protein (BiP), an essential and ubiquitous Hsp70 chaperone in the ER, plays a key role in protein folding and quality control. BiP contains two functional domains: a nucleotide-binding domain (NBD) and a substrate-binding domain (SBD). NBD binds and hydrolyzes ATP; the substrates for SBD are extended polypeptides. ATP binding allosterically accelerates polypeptide binding and release. Although crucial to the chaperone activity, the molecular mechanisms of polypeptide binding and allosteric coupling of BiP are poorly understood. Here, we present crystal structures of an intact human BiP in the ATP-bound state, the first intact eukaryotic Hsp70 structure, and isolated BiP-SBD with a peptide substrate bound representing the ADP-bound state. These structures and our biochemical analysis demonstrate that BiP has a unique NBD-SBD interface that is highly conserved only in eukaryotic Hsp70s found in the cytosol and ER to fortify its ATP-bound state and promote the opening of its polypeptide-binding pocket.