1TU3

Crystal Structure of Rab5 complex with Rabaptin5 C-terminal Domain

Summary for 1TU3

• Entry DOI: 10.2210/pdb1tu3/pdb
• Descriptor: Ras-related protein Rab-5A, Rab GTPase binding effector protein 1, MAGNESIUM ION, ... (5 entities in total)
• Functional Keywords: rab5, rabaptin5, effector-binding, protein transport
• Biological source: Homo sapiens (human); More
• Cellular location: Cell membrane; Lipid-anchor; Cytoplasmic side (By similarity): P20339; Cytoplasm: Q15276
• Total number of polymer chains: 10
• Total formula weight: 143707.54

Authors

Zhu, G.,Zhai, P.,Liu, J.,Terzyan, S.,Li, G.,Zhang, X.C. (deposition date: 2004-06-24, release date: 2004-10-05, Last modification date: 2023-08-23)

Primary citation

Zhu, G.,Zhai, P.,Liu, J.,Terzyan, S.,Li, G.,Zhang, X.C.
Structural basis of Rab5-Rabaptin5 interaction in endocytosis
Nat.Struct.Mol.Biol., 11:975-983, 2004

PubMed Abstract: 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.

PubMed: 15378032
DOI: 10.1038/nsmb832

Experimental method

X-RAY DIFFRACTION (2.31 Å)