The stereochemical course of group II intron self-splicing.
The stereochemical course of group II intron self-splicing.
复制标题
II组内含子自剪接的立体化学过程。
DOI：
10.1126/science.7527587
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Perlman,PS
中科院分区：
文献类型：
--
作者：
Padgett,RA;Podar,M;Boulanger,SC;Perlman,PS
通过5‘和3’剪接位磷二酯键上的硫代磷代换，确定了第II类内含子两个自剪接步骤的立体化学特性和反应历程。剪接反应的两个步骤都是在P构型中使用硫代磷酸进行的，但被Rp非对映异构体阻止。这两个步骤还进行了围绕磷的立体化学构型的反转，与协调的酯交换反应一致。这些结果与核前体mRNA(Pre-mRNA)剪接的结果一致，支持了II组内含子和核Pre-mRNA内含子具有共同进化史的假设。
The stereochemical specificities and reaction courses for both self-splicing steps of a group II intron have been determined by phosphorothioate substitution at the 5′ and 3′ splice site phosphodiester bonds. Both steps of the splicing reaction proceeded with a phosphorothioate in theSp configuration but were blocked by theRp diastereomer. Both steps also proceeded with inversion of stereochemical configuration around phosphorus, consistent with a concerted transesterification reaction. These results are identical to those found for nuclear precursor mRNA (pre-mRNA) splicing and provide support for the hypothesis that group II introns and nuclear pre-mRNA introns share a common evolutionary history.