Journal of Muscle Research & Cell Motility

, Volume 15, Issue 6, pp 587–594 | Cite as

Role of myosin light chains

  • Kathleen M. Trybus
Review Article


All conventional myosin IIs, whether isolated from skeletal, smooth, or invertebrate muscle sources, have two heads attached to an extended 16 nm α-helical coiled-coil tail. The head can be divided into a globular motor domain of ≈770 amino acids that contains the catalytic and actin binding sites, and a neck region of ≈70 amino acids which binds one essential and one regulatory light chain (ELC and RLC). The neck region with its associated LCs plays both structural and regulatory roles. While the mechanism and extent of regulation by the LCs varies for different myosins, the structural role may be a more fundamental feature of myosin II motors. Our understanding of the neck region has advanced rapidly in recent years primarily because of two types of information: (1) the high resolution structures of the LC binding domain from the thick-filament regulated scallop myosin (Xie et al., 1994) and of the head of unregulated skeletal myosin (Rayment et al., 1993), and (2) the ability to remove and/or mutate portions of both the heavy and light chains for analysis by in vitro motility assays.


Light Chain Neck Region Myosin Light Chain Structural Role Motor Domain 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • Kathleen M. Trybus
    • 1
  1. 1.Rosenstiel Basic Medical Sciences Research CenterBrandeis UniversityWalthamUSA

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