Opening of nucleic-acid double strands by helicases:: Active versus passive opening -: art. no. 011904
Opening of nucleic-acid double strands by helicases:: Active versus passive opening -: art. no. 011904
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DOI：
10.1103/physreve.71.011904
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发表时间：
2005-01-01
影响因子：
2.4
通讯作者：
Jülicher, F
中科院分区：
文献类型：
--
作者：
Betterton, MD;Jülicher, F
解旋酶蛋白沿着双链核酸分子移动并解开双螺旋。本文对解旋酶易位与双解旋之间的耦合进行了理论研究。通常区分两种不同的情况——主动开口和被动开口。在主动打开中，解旋酶直接破坏双链核酸（dsNA）的稳定性，促进打开。被动打开意味着解旋酶结合可用的ssNA时，热波动部分打开dsNA。我们建立了解旋酶运动的离散模型。相互作用势描述了当在单链和双链NA之间的连接处附近时解旋酶如何影响双解绕。电势的不同选择对应于主动开放和被动开放的情况。相互作用电位的最佳选择导致解旋酶可以像在单链上易位一样快速地解开NA。
Helicase proteins move along double-stranded nucleic-acid molecules and unwind the double helix. This paper presents a theoretical study of the coupling between helicase translocation and duplex unwinding. Two different cases-active and passive opening-are usually distinguished. In active opening, the helicase directly destabilizes the double-stranded nucleic acid (dsNA) to promote opening. Passive opening implies that the helicase binds ssNA available when a thermal fluctuation partially opens the dsNA. We formulate a discrete model for helicase motion. An interaction potential describes how the helicase affects duplex unwinding when near a junction between single-stranded and double-stranded NA. Different choices of the potential correspond to the cases of active and passive opening. An optimal choice of interaction potential leads to a helicase which can unwind NA as rapidly as it translocates on single strands.