Myosin IV

Myosin IV

Page updated 26/5/02

The first member of this group was the Heavy Molecular Weight myosin from Acanthamoeba castellanii (Horowitz & Hammer, 1990). Myosin IV resembles myosin I in that it seems to monomeric lacking as it does an apparent coiled-coil region. This myosin is 177kDa but gets its name in view of the fact that its tail at about 800aas is approximately twice the size of the myosin I cDNAs available for comparison at the time. Myosin IV contains an SH3 domain at the extreme C terminus. So far myosin IV has only been found in Acanthamoeba, a somewhat similar gene exists in Dictyostelium, MyoM but it is not similar enough to be classified as a myosin IV (Berg et al, 2001). Dictyostelium MyoM probably represents yet another class of myosin!

A. Myosin IV is a dimeric myosin

References:-

Berg, J. S., Powell, B. C. & Cheney, R. E. (2001) A millennial myosin census., Mol.Biol.Cell. 12, 780-794.

Horowitz, J. A. & Hammer III, J. A. (1990) A new Acanthamoeba myosin heavy chain. Cloning of the gene and immunological identification of the polypeptide., J.Biol.Chem. 265, 646-652.