Hjc resolvase is a distantly related member of the type II restriction endonuclease family
Hjc resolvase is a distantly related member of the type II restriction endonuclease family
复制标题
DOI：
10.1093/nar/28.22.4540
复制
发表时间：
2000-11-15
影响因子：
14.9
通讯作者：
Toh, H
中科院分区：
文献类型：
--
作者：
Daiyasu, H;Komori, K;Toh, H
Hjc解离酶是一种古细菌酶，参与霍利迪连接中间体处的同源DNA重组。然而，该酶的结构和催化机制尚未被确定，我们利用Pyrococcus furiosus的氨基酸序列进行数据库检索，共检测到59个氨基酸序列与Hjc解离酶有微弱但显著的序列相似性，检测到的序列包括Dpn II、Hae II和Vsr内切酶，它们属于II型限制性内切酶家族。此外，对检测到的序列进行多重比对，发现了一个高度保守的区域，该区域与II型限制性内切酶的活性位点相似，我们用Ala取代了Hjc解离酶高度保守区域中的三个保守氨基酸残基，使酶失活。实验研究和数据库检索结果表明，Hjc解离酶是II型限制性内切核酸酶家族的一个远亲成员。此外，我们的数据库检索结果表明，RecB结构域超家族的成员与II型限制性内切核酸酶家族在进化上相关。
Hjc resolvase is an archaeal enzyme involved in homologous:DNA recombination at the Holliday junction intermediate. However, the structure and the catalytic mechanism of the enzyme have not yet been identified, We performed database searching using the amino acid sequence of the enzyme from Pyrococcus furiosus as a query, We detected 59 amino acid sequences showing weak but significant sequence similarity to the Hjc resolvase, The detected sequences included DpnII, HaeII and Vsr endonuclease, which belong to the type II restriction endonuclease family. In addition, a highly conserved region Was identified from a multiple alignment of the detected sequences, which was similar to an active site of the type II restriction endonucleases, We substituted three conserved amino acid residues in the highly conserved region of the Hjc resolvase with Ala residues, The amino acid replacements inactivated the: enzyme. The experimental study, together with the: results of the database searching, suggests that the Hjc resolvase is a distantly related member of the type II restriction endonuclease family, In addition, the-results of our database searches suggested that the: members of the RecB domain superfamily are evolutionarily related to the type II restriction endo-nuclease family.