Open AccessThe contractile proteins of dictyostelium discoideum
Author(s) -
Spudich James A.,
Clarke Margaret
Publication year - 1974
Publication title -
journal of supramolecular structure
Language(s) - English
Resource type - Journals
eISSN - 1547-9366
pISSN - 0091-7419
DOI - 10.1002/jss.400020209
Subject(s) - dictyostelium discoideum , myosin , dictyostelium , actin , myosin light chain kinase , microbiology and biotechnology , biology , amoeba (genus) , biochemistry , gene
We have purified actin and my osin‐like proteins from amoebae of Dictyostelium discoideum. These proteins are very similar in their physical and enzymatic properties to muscle actin and myosin. Most importantly, they form thin and thick filaments, respectively, and Dictyostelium actin activates Dictyostelium myosin ATPase activity. Actin from these amoebae appears to be identical in size to muscle actin. The Dictyostelium myosin consists of two heavy chains of about 210,000 daltons and two classes of light chains, about 18,000 and 16,000 daltons. The heavy chains are slightly larger than those of muscle myosin. Biochemical and structural studies of membrane association of the contractile complex suggests that some of the amoeba actin is membrane‐bound and acts as an attachment point for myosin and other actin filaments.