PDBsum entry 4pgv

Membrance protein

PDB id: 4pgv

Contents

Protein chain

207 a.a.

Waters ×13

PDB id:

4pgv

Name:

Membrance protein

Title:

Crystal structure of yetj from bacillus subtilis at ph 8 by back soaking

Structure:

Uncharacterized protein yetj. Chain: a. Engineered: yes

Source:

Bacillus subtilis. Organism_taxid: 224308. Strain: 168. Gene: yetj, bsu07200. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.61Å R-factor: 0.226 R-free: 0.271

Authors:

Q.Liu,Y.Chang,W.A.Hendrickson,New York Consortium On Membrane Protein Structure (Nycomps)

Key ref:

Y.Chang et al. (2014). Structural basis for a pH-sensitive calcium leak across membranes. Science, 344, 1131-1135. PubMed id: 24904158 DOI: 10.1126/science.1252043

Date:

02-May-14 Release date: 04-Jun-14

Protein chain

O31539  (YETJ_BACSU) -  Uncharacterized protein YetJ from Bacillus subtilis (strain 168)

Seq: 214 a.a.

Struc: 207 a.a.

DOI no: 10.1126/science.1252043

Science 344:1131-1135 (2014)

PubMed id: 24904158

Structural basis for a pH-sensitive calcium leak across membranes.

Y.Chang, R.Bruni, B.Kloss, Z.Assur, E.Kloppmann, B.Rost, W.A.Hendrickson, Q.Liu.

ABSTRACT

Calcium homeostasis balances passive calcium leak and active calcium uptake. Human Bax inhibitor-1 (hBI-1) is an antiapoptotic protein that mediates a calcium leak and is representative of a highly conserved and widely distributed family, the transmembrane Bax inhibitor motif (TMBIM) proteins. Here, we present crystal structures of a bacterial homolog and characterize its calcium leak activity. The structure has a seven-transmembrane-helix fold that features two triple-helix sandwiches wrapped around a central C-terminal helix. Structures obtained in closed and open conformations are reversibly interconvertible by change of pH. A hydrogen-bonded, pKa (where Ka is the acid dissociation constant)-perturbed pair of conserved aspartate residues explains the pH dependence of this transition, and biochemical studies show that pH regulates calcium influx in proteoliposomes. Homology models for hBI-1 provide insights into TMBIM-mediated calcium leak and cytoprotective activity.