Brain myosin-V is a two-headed unconventional myosin with motor activity.
Chicken myosin-V is a member of a recently recognized class of myosins distinct from both the myosins-I and the myosins-II. We report here the purification, electron microscopic visualization, and motor properties of a protein of this class. Myosin-V molecules consist of two heads attached to an approximately 30 nm stalk that ends in a globular region of unknown function. Myosin-V binds to and decorates F-actin, has actin-activated magnesium-ATPase activity, and is a barbed-end-directed motor capable of moving actin filaments at rates of up to 400 nm/s. Myosin-V does not form filaments. Each myosin-V heavy chain is associated with approximately four calmodulin light chains as well as two less abundant proteins of 23 and 17 kd.
Cheney
R E
RE
Department of Biology, Yale University, New Haven, Connecticut 06511.
O'Shea
M K
MK
Heuser
J E
JE
Coelho
M V
MV
Wolenski
J S
JS
Espreafico
E M
EM
Forscher
P
P
Larson
R E
RE
Mooseker
M S
MS
D000199:Actins / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism; D002148:Calmodulin-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D002645:Chickens; D004533:Egtazic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005613:Freeze Etching; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008961:Models, Structural; D024701:Myosin Type V; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure
D000199:Actins; D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D046911:Macromolecular Substances; D009419:Nerve Tissue Proteins; C078829:chicken brain myosin-V p190; D004533:Egtazic Acid; D024701:Myosin Type V