An extended microtubule-binding structure within the dynein motor domain
An extended microtubule-binding structure within the dynein motor domain
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DOI：
10.1038/37663
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发表时间：
1997-12-11
期刊：
影响因子：
64.8
通讯作者：
Vallee, RB
中科院分区：
文献类型：
--
作者：
Gee, MA;Heuser, JE;Vallee, RB
鞭毛动力蛋白于 30 多年前被发现，是第一个能够沿着微管产生力的运动蛋白 (1)。动力蛋白的细胞质形式也已被鉴定，它参与有丝分裂和广泛的其他细胞内运动(2)（参考文献 3 中综述）。在了解驱动蛋白和肌球蛋白产生力的机制方面取得了快速进展(4-8)。相比之下，对动力蛋白的理解进展受到其巨大尺寸（相对分子质量 1,000K-2,000K）和亚基复杂性的限制。我们现在报告的证据表明，532K 力产生重链亚基的整个羧基末端的三分之二是 ATP 结合活性所必需的。我们进一步鉴定了一个微管结合域，令人惊讶的是，它位于整个 ATP 酶区域的下游，预计会形成发夹状茎。重组片段的直接超微结构分析证实了这一模型，并表明动力蛋白产生力的机制与其他运动蛋白的机制有很大不同。
Flagellar dynein was discovered over 30 years ago as the first motor protein capable of generating force along microtubules(1). A cytoplasmic form of dynein has also been identified which is involved in mitosis and a wide range of other intracellular movement(2) (reviewed in ref. 3). Rapid progress has been made on understanding the mechanism of force production by kinesins and myosins(4-8). In contrast, progress in understanding the dyneins has been limited by their great size (relative molecular mass 1,000K-2,000K) and subunit complexity. We now report evidence that the entire carboxy-terminal two-thirds of the 532K force-producing heavy chain subunit is required for ATP-binding activity. We further identify a microtubule-binding domain, which, surprisingly, lies well downstream of the entire ATPase region and is predicted to form a hairpin-like stalk Direct ultrastructural analysis of a recombinant fragment confirms this model, and suggests that the mechanism for dynein force production differs substantially from that of other motor proteins.