6ian
T. brucei IFT22/74/81 GTP-bound crystal structureT. brucei IFT22/74/81 GTP-bound crystal structure
Structural highlights
Publication Abstract from PubMedIntraflagellar transport (IFT) relies on motor proteins and the IFT complex to construct cilia and flagella. The IFT complex subunit IFT22/RabL5 has sequence similarity with small GTPases although the nucleotide specificity is unclear because of non-conserved G4/G5 motifs. We show that IFT22 specifically associates with G-nucleotides and present crystal structures of IFT22 in complex with GDP, GTP, and with IFT74/81. Our structural analysis unravels an unusual GTP/GDP-binding mode of IFT22 bypassing the classical G4 motif. The GTPase switch regions of IFT22 become ordered upon complex formation with IFT74/81 and mediate most of the IFT22-74/81 interactions. Structure-based mutagenesis reveals that association of IFT22 with the IFT complex is essential for flagellum construction in Trypanosoma brucei although IFT22 GTP-loading is not strictly required. Binding of IFT22 to the intraflagellar transport complex is essential for flagellum assembly.,Wachter S, Jung J, Shafiq S, Basquin J, Fort C, Bastin P, Lorentzen E EMBO J. 2019 Apr 2. pii: embj.2018101251. doi: 10.15252/embj.2018101251. PMID:30940671[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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