title: AAA domains and organization of the dynein motor unit.
abstract: Dyneins contain one-three microtubule motor units that are each derived from the C-terminal globular head of a heavy chain. The N-terminal regions of the heavy chains form stems that are required for intra-dynein associations. The microtubule-binding sites are located at the terminus of a short stalk that emanates from each globular head. Recent electron microscopic analysis indicates that the dynein head has a heptameric toroidal organization. This finding is echoed by the identification of six AAA (ATPases associated with cellular activities) domains and a seventh unrelated unit within this heavy chain region. At least two of these AAA domains can bind nucleotide, although only one appears able to hydrolyze ATP. Several other AAA domain proteins exhibit a similar annular organization of six AAA units. Detailed structural information is available for several AAA proteins, including N-ethylmaleimide-sensitive vesicle-fusion protein and the RuvB motor involved in DNA migration and resolution of Holliday junctions. The resulting structural parallels allow intriguing predictions to be made concerning dynein organization and motor function.
authors.affiliation: Department of Biochemistry, University of Connecticut Health Center, Farmington, CT 06032-3305, USA. steve@king2.uchc.edu
authors.forename: S M
authors.initials: SM
authors.lastname: King
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D000255:Adenosine Triphosphate / Q000737:chemistry; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry; D002696:Chlamydomonas / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D004398:Dyneins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D008870:Microtubules / Q000378:metabolism; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D008969:Molecular Sequence Data; D009068:Movement / Q000502:physiology; D052066:N-Ethylmaleimide-Sensitive Proteins; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D033921:Vesicular Transport Proteins
chemical_list: D002352:Carrier Proteins; D020409:Molecular Motor Proteins; D033921:Vesicular Transport Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D004398:Dyneins; D052066:N-Ethylmaleimide-Sensitive Proteins