1tu4
| |||||||
| , resolution 2.20Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , and | ||||||
| Gene: | RAB5A, RAB5 (Homo sapiens) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of Rab5-GDP Complex
OverviewOverview
Rab5 is a small GTPase that regulates early endosome fusion. We present here the crystal structure of the Rab5 GTPase domain in complex with a GTP analog and the C-terminal domain of effector Rabaptin5. The proteins form a dyad-symmetric Rab5-Rabaptin5(2)-Rab5 ternary complex with a parallel coiled-coil Rabaptin5 homodimer in the middle. Two Rab5 molecules bind independently to the Rabaptin5 dimer using their switch and interswitch regions. The binding does not involve the Rab complementarity-determining regions. We also present the crystal structures of two distinct forms of GDP-Rab5 complexes, both of which are incompatible with Rabaptin5 binding. One has a dislocated and disordered switch I but a virtually intact switch II, whereas the other has its beta-sheet and both switch regions reorganized. Biochemical and functional analyses show that the crystallographically observed Rab5-Rabaptin5 complex also exists in solution, and disruption of this complex by mutation abrogates endosome fusion.
About this StructureAbout this Structure
1TU4 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis of Rab5-Rabaptin5 interaction in endocytosis., Zhu G, Zhai P, Liu J, Terzyan S, Li G, Zhang XC, Nat Struct Mol Biol. 2004 Oct;11(10):975-83. Epub 2004 Sep 19. PMID:15378032
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