2k6s
Structure of Rab11-FIP2 C-terminal Coiled-coil Domain
Structural highlights
FunctionRFIP2_HUMAN A Rab11 effector protein acting in the regulation of the transport of vesicles from the endosomal recycling compartment (ERC) to the plasma membrane. Also involved in receptor-mediated endocytosis and membrane trafficking of recycling endosomes, probably originating from clathrin-coated vesicles. Binds preferentially to phosphatidylinositol 3,4,5-trisphosphate (PtdInsP3) and phosphatidic acid (PA). Required in a complex with MYO5B and RAB11 for the transport of NPC1L1 to the plasma membrane. Also acts as a regulator of cell polarity.[1] [2] [3] [4] 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 PubMedRab11 plays a central role in plasma membrane recycling which returns cellular receptors for reuse at the cell surface. A recently identified family of Rab11 interacting proteins (FIP) includes FIP2. The C-terminal region of FIP2 is essential for colocalization with Rab11 on early endosomes and for enabling formation of higher-order oligomers. Rab11 binding and oligomerization of FIP2 are separable. Here we have determined the three-dimensional structure of the 40-residue coiled-coil oligomerization domain of FIP2 in the absence of Rab11 using NMR methods. The N-terminal half showed strong NOE cross-peaks and well-dispersed NMR resonances, whereas the C-terminal half had fewer NOE cross-peaks and less chemical shift dispersion. The 10 C-terminal residues were mostly disordered. The final structures of the dimer had favorable Ramachandran angles and a root-mean-square deviation of 0.59 +/- 0.13 A over superimposed backbone residues. The structure allows a comparison to a structure of FIP2 in complex with Rab11 that was determined crystallographically. In complex with Rab11, the C-terminal residues are not disordered but have a helical structure that predicts residual dipolar coupling constants that are incompatible with those measured on the unbound FIP2. In both structures, a histidine residue is found at the normally hydrophobic position of the heptad repeat of the coiled coil, and here we show its ionization destabilizes the coiled-coil structure. Together, these data allow us to build a model in which the binding of FIP family proteins to Rab11 can be described in terms of conformational changes and that suggests new modes of regulation. Disorder and structure in the Rab11 binding domain of Rab11 family interacting protein 2.,Wei J, Liu Y, Bose K, Henry GD, Baleja JD Biochemistry. 2009 Jan 27;48(3):549-57. PMID:19119858[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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