Eoff R L, Raney K D
Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, 4301 W. Markham St. Slot 516, Little Rock, AR 72205, USA.
Biochem Soc Trans. 2005 Dec;33(Pt 6):1474-8. doi: 10.1042/BST0331474.
Helicases are molecular-motor enzymes that manipulate DNA or RNA during replication, repair, recombination, transcription, translation and processing of nucleic acids. The mechanisms for helicase activity have been studied intensely over the past decade. Recent advances in our understanding of the helicase mode of action have led to a general convergence of models that describe this diverse class of enzymes. One mechanism has been proposed that appears to have withstood the test of time, namely the inchworm mechanism. As the name implies, this mechanism involves a process whereby a helicase maintains at least two sites of contact with the nucleic acid. These binding sites can move relative to one another in a sequential fashion, resulting in net movement of the enzyme along the nucleic acid. The inchworm mechanism appears to be applicable to oligomeric states beyond the simple monomeric molecular motor. Although there are certainly many pertinent questions that remain unanswered, striking similarities in both form and function of seemingly disparate enzymes are becoming evident.
解旋酶是一类分子运动酶，在核酸的复制、修复、重组、转录、翻译及加工过程中操控DNA或RNA。在过去十年里，人们对解旋酶活性机制进行了深入研究。近年来，我们对解旋酶作用模式的理解取得了进展，使得描述这类多样酶的模型逐渐趋同。有人提出了一种似乎经受住了时间考验的机制，即尺蠖机制。顾名思义，该机制涉及一个过程，解旋酶与核酸至少保持两个接触位点。这些结合位点能以连续方式相对彼此移动，导致酶沿核酸产生净移动。尺蠖机制似乎适用于除简单单体分子运动酶之外的寡聚状态。尽管肯定还有许多相关问题尚未得到解答，但看似不同的酶在形式和功能上的显著相似性正变得日益明显。
