Sweeney H Lee, Houdusse Anne
Department of Physiology University of Pennsylvania School of Medicine, 3700 Hamilton Walk, Philadelphia, PA 19104-6085 USA.
Curr Opin Cell Biol. 2007 Feb;19(1):57-66. doi: 10.1016/j.ceb.2006.12.005. Epub 2006 Dec 18.
The recently solved structure of the myosin VI motor demonstrates that the unique insert at the end of the motor is responsible for the reversal of the normal myosin directionality. A second class-specific insert near the nucleotide-binding pocket contributes to myosin VI's unique kinetic tuning, allowing it to function either as an actin-based transporter or as an anchoring protein. Recent biochemical and biophysical studies have shown that the native molecule can form dimers upon clustering, and cell biological studies have demonstrated that it clearly does play both transport and anchoring roles in cells. These mechanistic insights allow us to speculate on how unusual aspects of myosin VI structure and function allow it to fill unique niches in cells.
最近解析出的肌球蛋白VI马达结构表明，马达末端独特的插入片段导致了正常肌球蛋白方向性的反转。靠近核苷酸结合口袋的另一个类别特异性插入片段有助于肌球蛋白VI独特的动力学调节，使其既能作为基于肌动蛋白的转运蛋白发挥作用，又能作为锚定蛋白发挥作用。最近的生物化学和生物物理学研究表明，天然分子在聚集时可形成二聚体，细胞生物学研究也已证明，它在细胞中确实发挥着运输和锚定作用。这些机制上的见解使我们能够推测，肌球蛋白VI结构和功能的异常方面是如何使其在细胞中占据独特的生态位的。
