Suh Y A, Kumar P K, Taira K, Nishikawa S
National Institute of Bioscience and Human Technology, MITI, Ibaraki, Japan.
Nucleic Acids Res. 1993 Jul 11;21(14):3277-80. doi: 10.1093/nar/21.14.3277.
To identify the divalent metal ions that can support the self-cleavage activity of the genomic ribozyme of human hepatitis delta virus (HDV), we tested the activity of various divalent metal ions in the ribozyme reactions catalyzed by HDV88 (683-770 nt) and 88DI3 (HDV88 with the sequence from 740-752 nt deleted). Among various metal ions tested, Mg2+, Mn2+, Ca2+ and Sr2+ efficiently supported the self-cleavage reactions of the HDV88 and 88DI3 ribozymes. In the case of the 88DI3 ribozyme, other divalent metal ions, such as Cd2+, Ba2+, Co2+, Pb2+ and Zn2+, were also able to support the self-cleavage reaction to some extent (< 10%). In the presence of spermidine (0.5 mM), the cleavage reaction was promoted at lower concentrations of effective divalent metal ions. The HDV ribozyme represents the only example of ribozyme to date of a ribozyme that catalyzes the self-cleavage reaction in the presence of Ca2+ ions as efficiently as it does in the presence of Mg2+ ions.
为了鉴定能够支持人丁型肝炎病毒（HDV）基因组核酶自切割活性的二价金属离子，我们在由HDV88（683 - 770 nt）和88DI3（缺失740 - 752 nt序列的HDV88）催化的核酶反应中测试了各种二价金属离子的活性。在所测试的各种金属离子中，Mg2 +、Mn2 +、Ca2 +和Sr2 +有效地支持了HDV88和88DI3核酶的自切割反应。对于88DI3核酶，其他二价金属离子，如Cd2 +、Ba2 +、Co2 +、Pb2 +和Zn2 +，也能够在一定程度上（<10%）支持自切割反应。在亚精胺（0.5 mM）存在的情况下，在较低浓度的有效二价金属离子时切割反应会得到促进。HDV核酶是迄今为止唯一一种在存在Ca2 +离子时催化自切割反应的效率与存在Mg2 +离子时一样高的核酶实例。
