title: Structural basis of motility in the microtubular axostyle: implications for cytoplasmic microtubule structure and function.
abstract: The gross morphology of the protozoan microtubule axostyle of Saccinobaculus ambloaxostylus can now be described in macromolecular detail. The left-handed coil of the axostyle is seen to be dependent upon the asymmetry inherent in the constituent microtubules as expressed by the specific array of linkages between microtubules and by a possible tendency for microtubules to coil into left-handed helices. The laminated sheets of microtubules are not aligned parallel to the long axis of the organelle, but become increasingly tilted off-axis as one descends through the sheets of microtubules from the convex to the concave surface of the axostyle. Fine-structural analysis of the axostyle indicates similarities of the linkages to dynein. The potential loci of the force-generating protein(s) are discussed as well as implications of the axostyle's structure on general microtubule function.
mesh_terms: D000818:Animals; D004398:Dyneins / Q000378:metabolism; D056890:Eukaryota / Q000648:ultrastructure*; D008870:Microtubules / Q000502:physiology* / Q000648:ultrastructure; D009068:Movement; D014404:Tubulin / Q000378:metabolism
chemical_list: D014404:Tubulin; D004398:Dyneins