Characterization of outer arm dynein in sea anemone, Anthopleura midori

Outer arm dynein was purified from sperm flagella of a sea anemone, Anthopl eura midori, and its biochemical and biophysical properties were characteri zed. The dynein, obtained at a 20S ATPase peak by sucrose density gradient centrifugation, consisted of two heavy chains, three intermediate chains, a nd seven light chains. The specific ATPase activity of dynein was 1.3 mu mo l Pi/mg/min. Four polypeptides (296, 296, 225, and 206 kDa) were formed by UV cleavage at 365 nm of dynein in the presence of vanadate and ATP. In add ition, negatively stained images of dynein molecules and the hook-shaped im age of the outer arm of the flagella indicated that sea anemone outer arm d ynein is two-headed. In contrast to protist dyneins, which are three-headed , outer arm dyneins of flagella and cilia in multicellular animals are two- headed molecules corresponding to the two heavy chains. Phylogenetic consid erations were made concerning the diversity of outer arm dyneins. (C) 1999 Wiley-Liss, Inc.