6ixq
Structure of Myo2-GTD in complex with Smy1
Structural highlights
FunctionMYO2_YEAST Myosin heavy chain that is required for the cell cycle-regulated transport of various organelles and proteins for their segregation. Functions by binding with its tail domain to receptor proteins on organelles and exerting force with its N-terminal motor domain against actin filaments, thereby transporting its cargo along polarized actin cables. Essential for the delivery of secretory vesicles to sites of active growth during bud emergence and cytokinesis. Required for segregation and inheritance of peroxisomes, late Golgi compartments, mitochondria and the vacuole to the daughter cell during cell division. Also required for correct alignment of the spindle during mitosis.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedClass V myosins are actin-dependent motors, which recognize numerous cellular cargos mainly via the C-terminal globular tail domain (GTD). Myo2, a yeast class V myosin, can transport a broad range of organelles. However, little is known about the capacity of Myo2-GTD to recognize such a diverse array of cargos specifically at the molecular level. Here, we solved crystal structures of Myo2-GTD (at 1.9-3.1 A resolutions) in complex with three cargo adaptor proteins: Smy1 (for polarization of secretory vesicles), Inp2 (for peroxisome transport), and Mmr1 (for mitochondria transport). The structures of Smy1- and Inp2-bound Myo2-GTD, along with site-directed mutagenesis experiments, revealed a binding site in subdomain-I having a hydrophobic groove with high flexibility enabling Myo2-GTD to accommodate different protein sequences. The Myo2-GTD-Mmr1 complex structure confirmed and complemented a previously identified mitochondrion/vacuole-specific binding region. Moreover, differences between the conformations and locations of cargo-binding sites identified here for Myo2 and those reported for mammalian MyoVA (MyoVA) suggest that class V myosins potentially have co-evolved with their specific cargos. Our structural and biochemical analysis not only uncovers a molecular mechanism that explains the diverse cargo recognition by Myo2-GTD, but also provides structural information useful for future functional studies of class V myosins in cargo transport. Structural mechanism for versatile cargo recognition by the yeast class V myosin Myo2.,Tang K, Li Y, Yu C, Wei Z J Biol Chem. 2019 Apr 12;294(15):5896-5906. doi: 10.1074/jbc.RA119.007550. Epub, 2019 Feb 25. PMID:30804213[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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