PDBsum entry 1z3h

Protein transport

PDB id: 1z3h

Contents

Protein chains

925 a.a. *

Metals

_MG

* Residue conservation analysis

PDB id:

1z3h

Name:

Protein transport

Title:

The exportin cse1 in its cargo-free, cytoplasmic state

Structure:

Importin alpha re-exporter. Chain: a, b. Synonym: chromosome segregation protein cse1. Engineered: yes

Source:

Saccharomyces cerevisiae. Baker's yeast. Organism_taxid: 4932. Gene: cse1. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

3.10Å R-factor: 0.241 R-free: 0.288

Authors:

A.Cook,E.Fernandez,D.Lindner,J.Ebert,G.Schlenstedt,E.Conti

Key ref:

A.Cook et al. (2005). The structure of the nuclear export receptor Cse1 in its cytosolic state reveals a closed conformation incompatible with cargo binding. Mol Cell, 18, 355-367. PubMed id: 15866177 DOI: 10.1016/j.molcel.2005.03.021

Date:

12-Mar-05 Release date: 10-May-05

Protein chains

P33307  (CSE1_YEAST) -  Importin alpha re-exporter from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 960 a.a.

Struc: 925 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/j.molcel.2005.03.021

Mol Cell 18:355-367 (2005)

PubMed id: 15866177

The structure of the nuclear export receptor Cse1 in its cytosolic state reveals a closed conformation incompatible with cargo binding.

A.Cook, E.Fernandez, D.Lindner, J.Ebert, G.Schlenstedt, E.Conti.

ABSTRACT

Cse1 mediates nuclear export of importin alpha, the nuclear localization signal (NLS) import adaptor. We report the 3.1 A resolution structure of cargo-free Cse1, representing this HEAT repeat protein in its cytosolic state. Cse1 is compact, consisting of N- and C-terminal arches that interact to form a ring. Comparison with the structure of cargo-bound Cse1 shows a major conformational change leading to opening of the structure upon cargo binding. The largest structural changes occur within a hinge region centered at HEAT repeat 8. This repeat contains a conserved insertion that connects the RanGTP and importin alpha contact sites and that is essential for binding. In the cargo-free state, the RanGTP binding sites are occluded and the importin alpha sites are distorted. Mutations that destabilize the N- to C-terminal interaction uncouple importin alpha and Ran binding, suggesting that the closed conformation prevents association with importin alpha.

Selected figure(s)

Figure 4.
Figure 4. The Ring-like Structure of Cse1 Opens up to Assume a Horseshoe Shape upon Cargo Binding

Figure 5.
Figure 5. The Intramolecular Interaction between the N- and C-Terminal Arches Prevents Cargo Binding in the Absence of RanGTP

The above figures are reprinted by permission from Cell Press: Mol Cell (2005, 18, 355-367) copyright 2005.

Figures were selected by an automated process.