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Cryo-EM structure of the human inner arm dynein DNAH7 microtubule binding domain bound to microtubules
Structural highlights
DiseaseDYHC1_MOUSE Defects in Dync1h1 are the cause of the 'Legs at odd angles' (LOA) phenotype, an autosomal dominant trait where affected animals display unusual twisting of the body and clenching of the hindlimbs when suspended by the tail. Heterozygotes suffer age-related progressive loss of muscle tone and locomotor ability without major reduction in life-span while homozygotes show a more severe phenotype with an inability to move or feed, and die within 24 hours of birth. LOA mutants display defects in migration of facial motor neuron cell bodies and impaired retrograde transport in spinal cord motor neurons. Defects in Dync1h1 are the cause of the Cramping 1 (Cra1) phenotype, an autosomal dominant trait where affected animals display unusual twisting of the body and clenching of the hindlimbs when suspended by the tail. Heterozygotes suffer age-related progressive loss of muscle tone and locomotor ability without major reduction in life-span while homozygotes show a more severe phenotype with an inability to move or feed, and die within 24 hours of birth. FunctionDYHC1_MOUSE Cytoplasmic dynein 1 acts as a motor for the intracellular retrograde motility of vesicles and organelles along microtubules. Dynein has ATPase activity; the force-producing power stroke is thought to occur on release of ADP.DYH7_HUMAN Force generating protein of respiratory cilia. Produces force towards the minus ends of microtubules. Dynein has ATPase activity; the force-producing power stroke is thought to occur on release of ADP (By similarity). Publication Abstract from PubMedDyneins are motor proteins responsible for transport in the cytoplasm and the beating of axonemes in cilia and flagella. They bind and release microtubules via a compact microtubule-binding domain (MTBD) at the end of a coiled-coil stalk. We address how cytoplasmic and axonemal dynein MTBDs bind microtubules at near atomic resolution. We decorated microtubules with MTBDs of cytoplasmic dynein-1 and axonemal dynein DNAH7 and determined their cryo-EM structures using helical Relion. The majority of the MTBD is rigid upon binding, with the transition to the high-affinity state controlled by the movement of a single helix at the MTBD interface. DNAH7 contains an 18-residue insertion, found in many axonemal dyneins, that contacts the adjacent protofilament. Unexpectedly, we observe that DNAH7, but not dynein-1, induces large distortions in the microtubule cross-sectional curvature. This raises the possibility that dynein coordination in axonemes is mediated via conformational changes in the microtubule. Cryo-EM of dynein microtubule-binding domains shows how an axonemal dynein distorts the microtubule.,Lacey SE, He S, Scheres SH, Carter AP Elife. 2019 Jul 2;8. pii: 47145. doi: 10.7554/eLife.47145. PMID:31264960[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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