Suck D
Structural Biology Programme, European Molecular Biology Laboratory, Heidelberg, Germany.
Biopolymers. 1997;44(4):405-21. doi: 10.1002/(SICI)1097-0282(1997)44:4<405::AID-BIP5>3.0.CO;2-L.
The nucleases discussed in this review show little sequence specificity but instead recognize certain structural features of their respective DNA substrates. The level of their structural selectivity ranges from simple discrimination between single- and double-stranded DNA (nucleases P1 and S1), the recognition of helical parameters like groove width and flexibility (DNase I), the recognition of helical distortions caused by abasic sites (exonuclease III, HAP1), to the recognition of specialized structures like flap DNA (5'-nucleases of eukaryotes, phages, and eubacterial DNA polymerases) and four-way junctions (T4 endonuclease VII, RuvC). The discussion is focused on the structural basis of the recognition process. In most cases the available x-ray structures of the nucleases and/or their DNA complexes have revealed the presence of structural motifs explaining the observed structural selectivity.
本综述中讨论的核酸酶几乎没有序列特异性，而是识别其各自DNA底物的某些结构特征。它们的结构选择性水平范围广泛，从简单区分单链和双链DNA（核酸酶P1和S1），识别诸如凹槽宽度和柔韧性等螺旋参数（DNase I），识别由无碱基位点引起的螺旋扭曲（核酸外切酶III、HAP1），到识别诸如瓣状DNA（真核生物、噬菌体和真细菌DNA聚合酶的5'核酸酶）和四向接头（T4内切核酸酶VII、RuvC）等特殊结构。讨论聚焦于识别过程的结构基础。在大多数情况下，核酸酶和/或其DNA复合物的现有X射线结构揭示了一些结构基序的存在，这些结构基序解释了观察到的结构选择性。
