Katayanagi K, Miyagawa M, Matsushima M, Ishikawa M, Kanaya S, Ikehara M, Matsuzaki T, Morikawa K
Protein Engineering Research Institute, Osaka, Japan.
Nature. 1990 Sep 20;347(6290):306-9. doi: 10.1038/347306a0.
The three-dimensional structure of RNase H from Escherichia coli was determined at 1.8 A resolution by X-ray crystallography. The enzyme was found to belong to the alpha + beta class of structures, consisting of two distinct domains. The structure implies a possible region interacting with a DNA-RNA hybrid. The Mg2(+)-binding site essential for activity is located near a cluster of four acidic amino acids--one glutamic and three aspartic acid residues. These residues are completely conserved in the homology alignment of sequences of RNase H and reverse transcriptases from retroviruses and retrovirus-like entities. The structural motif of beta strands around the Mg2(+)-binding site has similarities to that in DNase I.
通过X射线晶体学以1.8埃的分辨率确定了来自大肠杆菌的核糖核酸酶H（RNase H）的三维结构。该酶属于α + β结构类别，由两个不同的结构域组成。该结构暗示了一个可能与DNA - RNA杂交体相互作用的区域。对活性至关重要的Mg2(+)结合位点位于四个酸性氨基酸簇附近，即一个谷氨酸和三个天冬氨酸残基。这些残基在来自逆转录病毒和类逆转录病毒实体的RNase H与逆转录酶序列的同源比对中完全保守。Mg2(+)结合位点周围的β链结构基序与脱氧核糖核酸酶I（DNase I）中的相似。
