PDBsum entry 4yg8

Transport protein

PDB id: 4yg8

Contents

Protein chains

276 a.a.

673 a.a.

Ligands

EPE

GOL

Waters ×203

PDB id:

4yg8

Name:

Transport protein

Title:

Crystal structure of the chs5-chs6 exomer cargo adaptor complex

Structure:

Chitin biosynthesis protein chs5. Chain: a. Engineered: yes. Chitin biosynthesis protein chs6. Chain: b. Synonym: protein csd3. Engineered: yes

Source:

Saccharomyces cerevisiae. Baker's yeast. Organism_taxid: 4932. Strain: sey6210. Gene: chs5. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: chs6, csd3, yjl099w, j0838.

Resolution:

2.75Å R-factor: 0.194 R-free: 0.230

Authors:

J.E.Paczkowski,B.C.Richardson,A.M.Strassner,J.C.Fromme

Key ref:

J.E.Paczkowski et al. (2012). The exomer cargo adaptor structure reveals a novel GTPase-binding domain. Embo J, 31, 4191-4203. PubMed id: 23000721

Date:

26-Feb-15 Release date: 11-Mar-15

Supersedes:

4gns

Protein chain

Q12114  (CHS5_YEAST) -  Chitin biosynthesis protein CHS5 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 671 a.a.

Struc: 276 a.a.*

Protein chain

P40955  (CHS6_YEAST) -  Chitin biosynthesis protein CHS6 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 746 a.a.

Struc: 673 a.a.

* PDB and UniProt seqs differ at 41 residue positions (black crosses)

Embo J 31:4191-4203 (2012)

PubMed id: 23000721

The exomer cargo adaptor structure reveals a novel GTPase-binding domain.

J.E.Paczkowski, B.C.Richardson, A.M.Strassner, J.C.Fromme.

ABSTRACT

Cargo adaptors control intracellular trafficking of transmembrane proteins by sorting them into membrane transport carriers. The COPI, COPII, and clathrin cargo adaptors are structurally well characterized, but other cargo adaptors remain poorly understood. Exomer is a specialized cargo adaptor that sorts specific proteins into trans-Golgi network (TGN)-derived vesicles in response to cellular signals. Exomer is recruited to the TGN by the Arf1 GTPase, a universally conserved trafficking regulator. Here, we report the crystal structure of a tetrameric exomer complex composed of two copies each of the Chs5 and Chs6 subunits. The structure reveals the FN3 and BRCT domains of Chs5, which together we refer to as the FBE domain (FN3-BRCT of exomer), project from the exomer core complex. The overall architecture of the FBE domain is reminiscent of the appendage domains of other cargo adaptors, although it exhibits a distinct topology. In contrast to appendage domains, which bind accessory factors, we show that the primary role of the FBE domain is to bind Arf1 for recruitment of exomer to membranes.