1TXU image
Entry Detail
PDB ID:
1TXU
Keywords:
PROTEIN TRANSPORT
Title:
Crystal Structure of the Vps9 Domain of Rabex-5
Biological Source:
Source Organism:
Homo sapiens
Host Organism:
Escherichia coli
PDB Version:
Deposition Date:
2004-07-06
Release Date:
2004-09-21
Method Details:
Experimental Method:
X-RAY DIFFRACTION
Resolution:
2.35 Å
R-Value Free:
0.26
R-Value Work:
0.22
R-Value Observed:
0.22
Space Group:
P 21 21 2
1TXU validation report
Macromolecular Entities
Protein Blast
Polymer Type:polypeptide(L)
Description:Rab5 GDP/GTP exchange factor
Chain IDs:A
Chain Length:273
Number of Molecules:1
Biological Source:Homo sapiens
UniProt ID:Q9UJ41 Pfam ID:PF18151, PF02204
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
MSE A MET SELENOMETHIONINE
Ligand Molecules
MG
Primary Citation
Structure, exchange determinants, and family-wide rab specificity of the tandem helical bundle and Vps9 domains of Rabex-5
Cell(Cambridge,Mass.) 118 607 617 (2004)
PMID: 15339665 DOI: 10.1016/j.cell.2004.08.009

Abstact

The Rab5 GTPase, an essential regulator of endocytosis and endosome biogenesis, is activated by guanine-nucleotide exchange factors (GEFs) that contain a Vps9 domain. Here, we show that the catalytic core of the Rab GEF Rabex-5 has a tandem architecture consisting of a Vps9 domain stabilized by an indispensable helical bundle. A family-wide analysis of Rab specificity demonstrates high selectivity for Rab5 subfamily GTPases. Conserved exchange determinants map to a common surface of the Vps9 domain, which recognizes invariant aromatic residues in the switch regions of Rab GTPases and selects for the Rab5 subfamily by requiring a small nonacidic residue preceding a critical phenylalanine in the switch I region. These and other observations reveal unexpected similarity with the Arf exchange site in the Sec7 domain.

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Primary Citation of related structures
1TXU