Nanobiotechnology Center, College of Pharmacy and Markey Cancer Center, University of Kentucky, Lexington, KY, USA.
Virology. 2013 Aug 15;443(1):20-7. doi: 10.1016/j.virol.2013.04.004. Epub 2013 May 22.
The AAA+ superfamily of proteins is a class of motor ATPases performing a wide range of functions that typically exist as hexamers. The ATPase of phi29 DNA packaging motor has long been a subject of debate in terms of stoichiometry and mechanism of action. Here, we confirmed the stoichiometry of phi29 motor ATPase to be a hexamer and provide data suggesting that the phi29 motor ATPase is a member of the classical hexameric AAA+ superfamily. Native PAGE, EMSA, capillary electrophoresis, ATP titration, and binomial distribution assay show that the ATPase is a hexamer. Mutations in the known Walker motifs of the ATPase validated our previous assumptions that the protein exists as another member of this AAA+ superfamily. Our data also supports the finding that the phi29 DNA packaging motor uses a revolution mechanism without rotation or coiling (Schwartz et al., this issue).
AAA+ 超家族蛋白是一类执行多种功能的马达 ATP 酶，通常以六聚体形式存在。phi29 DNA 包装马达的 ATP 酶在其计量学和作用机制方面一直存在争议。在这里，我们证实了 phi29 马达 ATP 酶的计量学为六聚体，并提供了数据表明 phi29 马达 ATP 酶是经典六聚体 AAA+ 超家族的成员。天然 PAGE、EMSA、毛细管电泳、ATP 滴定和二项式分布测定表明，ATP 酶是一个六聚体。在 ATP 酶的已知 Walker 基序上的突变验证了我们之前的假设，即该蛋白是这个 AAA+ 超家族的另一个成员。我们的数据还支持了 phi29 DNA 包装马达使用无旋转或卷曲的旋转机制的发现（Schwartz 等人，本期）。
