1txu

From Proteopedia

Crystal Structure of the Vps9 Domain of Rabex-5

Structural highlights

1txu is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.35Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RABX5_HUMAN Rab effector protein acting as linker between gamma-adaptin, RAB4A or RAB5A. Involved in endocytic membrane fusion and membrane trafficking of recycling endosomes. Stimulates nucleotide exchange on RAB5A. Can act as a ubiquitin ligase (By similarity).^[1] ^[2] ^[3]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

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.

Structure, exchange determinants, and family-wide rab specificity of the tandem helical bundle and Vps9 domains of Rabex-5.,Delprato A, Merithew E, Lambright DG Cell. 2004 Sep 3;118(5):607-17. PMID:15339665^[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Horiuchi H, Lippe R, McBride HM, Rubino M, Woodman P, Stenmark H, Rybin V, Wilm M, Ashman K, Mann M, Zerial M. A novel Rab5 GDP/GTP exchange factor complexed to Rabaptin-5 links nucleotide exchange to effector recruitment and function. Cell. 1997 Sep 19;90(6):1149-59. PMID:9323142
↑ Lippe R, Miaczynska M, Rybin V, Runge A, Zerial M. Functional synergy between Rab5 effector Rabaptin-5 and exchange factor Rabex-5 when physically associated in a complex. Mol Biol Cell. 2001 Jul;12(7):2219-28. PMID:11452015
↑ Delprato A, Merithew E, Lambright DG. Structure, exchange determinants, and family-wide rab specificity of the tandem helical bundle and Vps9 domains of Rabex-5. Cell. 2004 Sep 3;118(5):607-17. PMID:15339665 doi:10.1016/j.cell.2004.08.009
↑ Delprato A, Merithew E, Lambright DG. Structure, exchange determinants, and family-wide rab specificity of the tandem helical bundle and Vps9 domains of Rabex-5. Cell. 2004 Sep 3;118(5):607-17. PMID:15339665 doi:10.1016/j.cell.2004.08.009