title: Dynein arm substructure and the orientation of arm-microtubule attachments.
abstract: In the presence of AMP-PCP (beta, gamma-methyleneadenosine 5'-triphosphate), a non-hydrolyzable analog of ATP, negative stain images of increased morphological detail indicate that the dynein arm, attached to ciliary doublet microtubules, is composed of subunits including a cape, an elongated body and a head. The arrangement of these subunits makes it possible to distinguish A from B subfiber binding sites on a single arm and to demonstrate that the head of an extended arm on subfiber A of one ciliary doublet is capable of binding to subfiber B of an adjacent doublet in a specific orientation, which supports a key step in a current model of the mechanochemical cycle by which the arm produces microtubule sliding in the ciliary axoneme.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives; D000818:Animals; D004398:Dyneins / Q000378:metabolism; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure*; D011487:Protein Conformation; D013768:Tetrahymena / Q000032:analysis / Q000648:ultrastructure
chemical_list: D046911:Macromolecular Substances; C005147:5'-adenylyl (beta,gamma-methylene)diphosphonate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D004398:Dyneins; C002630:alpha,beta-methyleneadenosine 5'-triphosphate