Catalytically critical nucleotide in domain 5 of a group II intron.
Catalytically critical nucleotide in domain 5 of a group II intron.
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II 组内含子的结构域 5 中的催化关键核苷酸。
DOI：
10.1073/pnas.92.10.4422
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发表时间：
1995
影响因子：
11.1
通讯作者：
James S. Franzen
中科院分区：
文献类型：
--
作者：
C. Peebles;Mincheng Zhang;Philip S. Perlman;James S. Franzen
Domain 5 (D5) is a small hairpin structure within group II introns. A bimolecular assay system depends on binding by D5 to an intron substrate for self-splicing activity. In this study, mutations in D5 identify two among six nearly invariant nucleotides as being critical for 5' splice junction hydrolysis but unimportant for binding. A mutation at another site in D5 blocks binding. Thus, mutations can distinguish two D5 functions: substrate binding and catalysis. The secondary structure of D5 may resemble helix I formed by the U2 and U6 small nuclear RNAs in the eukaryotic spliceosome. Our results support a revision of the previously proposed correspondence between D5 and helix I on the basis of the critical trinucleotide 5'-AGC-3' present in both. We suggest that this trinucleotide plays a similar role in promoting the chemical reactions for both splicing systems.
