Reference Work Entry

Encyclopedia of Biophysics

pp 552-558

Dynein Family Classification

  • Aristides G. DiamantAffiliated withDivision of Structural Studies, Medical Research Council Laboratory of Molecular Biology Email author 
  • , Andrew P. CarterAffiliated withDivision of Structural Studies, Medical Research Council Laboratory of Molecular Biology

Synonyms

Molecular motors

Introduction

All known cytoskeletal molecular motors belong to one of three families: the dyneins, myosins, and kinesins. Each motor includes at least one heavy chain (HC), which contains a motor domain that converts the chemical energy of ATP into mechanical work as well as binding sites for various accessory chains. Despite these similarities in overall structure and function, the dyneins are distinct due to the size of their HCs. Dynein HCs (>500 kDa) are much larger than those of kinesin (∼70–170 kDa) and myosin (∼120–250 kDa). This disparity in size reflects the difference in evolutionary origin between dynein and the other two motor families. The highly conserved nucleotide binding pockets of kinesin and myosin are homologous to the active site of G proteins, while dynein’s hydrolytic activity relies on AAA+ domains. All three families are composed of several related, yet distinct members, each adapted to its unique cellular function. Th ...

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