Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan.
J Biol Chem. 2011 May 6;286(18):15815-20. doi: 10.1074/jbc.M110.201400. Epub 2011 Mar 18.
p97 is composed of two conserved AAA (ATPases associated with diverse cellular activities) domains, which form a tandem hexameric ring. We characterized the ATP hydrolysis mechanism of CDC-48.1, a p97 homolog of Caenorhabditis elegans. The ATPase activity of the N-terminal AAA domain was very low at physiological temperature, whereas the C-terminal AAA domain showed high ATPase activity in a coordinated fashion with positive cooperativity. The cooperativity and coordination are generated by different mechanisms because a noncooperative mutant still showed the coordination. Interestingly, the growth speed of yeast cells strongly related to the positive cooperativity rather than the ATPase activity itself, suggesting that the positive cooperativity is critical for the essential functions of p97.
p97 由两个保守的 AAA（与多种细胞活动相关的 ATP 酶）结构域组成，这些结构域形成串联的六聚体环。我们对 CDC-48.1 的 ATP 水解机制进行了表征，CDC-48.1 是秀丽隐杆线虫 p97 的同源物。生理温度下，N 端 AAA 结构域的 ATP 酶活性非常低，而 C 端 AAA 结构域以协调的方式表现出高 ATP 酶活性，且具有正协同性。协同性和协调性是由不同的机制产生的，因为非协同性突变体仍然表现出协调性。有趣的是，酵母细胞的生长速度与正协同性密切相关，而不是与 ATP 酶活性本身相关，这表明正协同性对于 p97 的基本功能至关重要。
