3r7w
From Proteopedia
Crystal Structure of Gtr1p-Gtr2p complex
Structural highlights
FunctionRAGAB_YEAST GTPase involved in activation of the TORC1 signaling pathway, which promotes growth and represses autophagy in nutrient-rich conditions (PubMed:26510498, PubMed:28993463, PubMed:32801125). Also required for TORC1 inactivation during nitrogen starvation (PubMed:28993463). Required for intracellular sorting of GAP1 out of the endosome (PubMed:16732272). Functionally associated with the inorganic phosphate transporter PHO84, and may be involved in regulating its function or localization (PubMed:1620108).[1] [2] [3] [4] [5] Publication Abstract from PubMedThe target of rapamycin (TOR) complex 1 (TORC1) is a central cell growth regulator in response to a wide array of signals. The Rag GTPases play an essential role in relaying amino acid signals to TORC1 activation through direct interaction with raptor and recruitment of the TORC1 complex to lysosomes. Here we present the crystal structure of the Gtr1p-Gtr2p complex, the Rag homologs from Saccharomyces cerevisiae, at 2.8 A resolution. The heterodimeric GTPases reveal a pseudo-twofold symmetric organization. Structure-guided functional analyses of RagA-RagC, the human homologs of Gtr1p-Gtr2p, show that both G domains (N-terminal GTPase domains) and dimerization are important for raptor binding. In particular, the switch regions of the G domain in RagA are indispensible for interaction with raptor, and hence TORC1 activation. The dimerized C-terminal domains of RagA-RagC display a remarkable structural similarity to MP1/p14, which is in a complex with lysosome membrane protein p18, and directly interact with p18, therefore recruiting mTORC1 to the lysosome for activation by Rheb. Our results reveal a structural model for the mechanism of the Rag GTPases in TORC1 activation and amino acid signaling. Crystal structure of the Gtr1p-Gtr2p complex reveals new insights into the amino acid-induced TORC1 activation.,Gong R, Li L, Liu Y, Wang P, Yang H, Wang L, Cheng J, Guan KL, Xu Y Genes Dev. 2011 Aug 15;25(16):1668-73. Epub 2011 Aug 4. PMID:21816923[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Large Structures | Saccharomyces cerevisiae | Cheng J | Gong R | Guan KL | Li L | Liu Y | Wang L | Wang P | Xu Y | Yang H
