PDBsum entry 4y1s

Immune system

PDB id: 4y1s

Contents

Protein chain

122 a.a.

Metals

_CA

Waters ×134

PDB id:

4y1s

Name:

Immune system

Title:

Structural basis for ca2+-mediated interaction of the perforin c2 domain with lipid membranes

Structure:

Perforin-1. Chain: a. Fragment: c2 domain (unp residues 410-535). Synonym: p1,cytolysin,lymphocyte pore-forming protein. Engineered: yes. Mutation: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Gene: prf1, pfp. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.61Å R-factor: 0.167 R-free: 0.185

Authors:

P.J.Conroy,H.Yagi,J.C.Whisstock,R.S.Norton

Key ref:

H.Yagi et al. (2015). Structural Basis for Ca2+-mediated Interaction of the Perforin C2 Domain with Lipid Membranes. J Biol Chem, 290, 25213-25226. PubMed id: 26306037 DOI: 10.1074/jbc.M115.668384

Date:

09-Feb-15 Release date: 02-Sep-15

Protein chain

P10820  (PERF_MOUSE) -  Perforin-1 from Mus musculus

Seq: 554 a.a.

Struc: 122 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

DOI no: 10.1074/jbc.M115.668384

J Biol Chem 290:25213-25226 (2015)

PubMed id: 26306037

Structural Basis for Ca2+-mediated Interaction of the Perforin C2 Domain with Lipid Membranes.

H.Yagi, P.J.Conroy, E.W.Leung, R.H.Law, J.A.Trapani, I.Voskoboinik, J.C.Whisstock, R.S.Norton.

ABSTRACT

Natural killer cells and cytotoxic T-lymphocytes deploy perforin and granzymes to kill infected host cells. Perforin, secreted by immune cells, binds target membranes to form pores that deliver pro-apoptotic granzymes into the target cell. A crucial first step in this process is interaction of its C2 domain with target cell membranes, which is a calcium-dependent event. Some aspects of this process are understood, but many molecular details remain unclear. To address this, we investigated the mechanism of Ca(2+) and lipid binding to the C2 domain by NMR spectroscopy and x-ray crystallography. Calcium titrations, together with dodecylphosphocholine micelle experiments, confirmed that multiple Ca(2+) ions bind within the calcium-binding regions, activating perforin with respect to membrane binding. We have also determined the affinities of several of these binding sites and have shown that this interaction causes a significant structural rearrangement in CBR1. Thus, it is proposed that Ca(2+) binding at the weakest affinity site triggers changes in the C2 domain that facilitate its interaction with lipid membranes.