Importance of the converter region for the motility of myosin as revealed by the studies on chimeric Chara myosins.
A long alpha-helix in myosin head constitutes a lever arm together with light chains. It is known from X-ray crystallographic studies that the first three turns of this lever arm alpha-helix are inserted into the converter region of myosin. We previously showed that chimeric Chara myosin in which the motor domain of Chara myosin was connected to the lever arm alpha-helix of Dictyostelium myosin had motility far less than that expected for the motor domain of Chara myosin. Here, we replaced the inserted three turns of alpha-helix of Dictyostelium myosin with that of the Chara myosin and found that the replacement enhanced the motility 2.6-fold without changing the ATPase activity so much. The result clearly showed the importance of interaction between the converter region and the lever arm alpha-helix for the efficient motility of myosin.
Seki
Masaya
M
Department of Biology, Chiba University, Inage-ku, 263-8522 Chiba, Japan.
Kashiyama
Taku
T
Hachikubo
You
Y
Ito
Kohji
K
Yamamoto
Keiichi
K
D000251:Adenosine Triphosphatases / Q000032:analysis / Q000378:metabolism; D000818:Animals; D044784:Chara / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D004023:Dictyostelium / Q000737:chemistry / Q000235:genetics; D056890:Eukaryota / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D008958:Models, Molecular; D009038:Motion; D018994:Myosin Light Chains / Q000737:chemistry; D009218:Myosins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013329:Structure-Activity Relationship
D018994:Myosin Light Chains; D011994:Recombinant Proteins; D000251:Adenosine Triphosphatases; D009218:Myosins