Abstract：
:Splicing of tRNA precursors in Saccharomyces cerevisiae extracts proceeds in two steps; excision of the intervening sequence and ligation of the tRNA halves. The ability to resolve these two steps and the distinct physical properties of the endonuclease and ligase suggested that the splicing steps may not be concerted and that these two enzymes may act independently in vivo. A ligase competition assay was developed to examine whether the excision and ligation steps in tRNA splicing in vitro are concerted or independent. The ability of either yeast ligase or T4 ligase plus kinase to join the tRNA halves produced by endonuclease and the distinct structures of the reaction products provided the basis for the competition assay. In control reactions, joining of isolated tRNA halves formed by preincubation with endonuclease was measured. The ratio of yeast to T4 reaction products in these control assays reflected the ratio of the enzyme activities, as would be expected if each has equal access to the substrate. In splicing competition assays, endonuclease and pre-tRNA were added to ligase mixtures, and joining of the halves that were formed was measured. In these assays the products were predominantly those of the yeast ligase even when the T4 enzymes were present in excess. These results demonstrate preferential access of yeast ligase to the endonuclease products and provide evidence for the assembly of a functional tRNA splicing complex in vitro. This observation has important implications for the organization of the splicing components and of the gene expression pathway in vivo.
journal_name
Mol Cell Bioljournal_title
Molecular and cellular biologyauthors
Greer CLdoi
10.1128/mcb.6.2.635subject
Has Abstractpub_date
1986-02-01 00:00:00pages
635-44issue
2eissn
0270-7306issn
1098-5549journal_volume
6pub_type
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pub_type： 杂志文章
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pub_type： 杂志文章
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pub_type： 杂志文章
doi：10.1128/mcb.6.10.3555
更新日期：1986-10-01 00:00:00
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pub_type： 杂志文章
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pub_type： 杂志文章
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pub_type： 杂志文章
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更新日期：1993-06-01 00:00:00
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pub_type： 杂志文章
doi：10.1128/mcb.15.4.1870
更新日期：1995-04-01 00:00:00
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更新日期：2002-09-01 00:00:00
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pub_type： 杂志文章
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更新日期：1994-04-01 00:00:00
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pub_type： 杂志文章
doi：10.1128/mcb.14.11.7660
更新日期：1994-11-01 00:00:00
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doi：10.1128/mcb.18.6.3395
更新日期：1998-06-01 00:00:00
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pub_type： 杂志文章
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更新日期：1997-11-01 00:00:00
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pub_type： 杂志文章
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更新日期：2004-04-01 00:00:00
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pub_type： 杂志文章
doi：10.1128/MCB.25.7.2525-2538.2005
更新日期：2005-04-01 00:00:00
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pub_type： 杂志文章
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更新日期：2003-08-01 00:00:00
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journal_title：Molecular and cellular biology
pub_type： 杂志文章
doi：10.1128/mcb.8.4.1845
更新日期：1988-04-01 00:00:00
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journal_title：Molecular and cellular biology
pub_type： 杂志文章
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更新日期：1991-06-01 00:00:00
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更新日期：2000-10-01 00:00:00
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pub_type： 杂志文章
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更新日期：2010-09-01 00:00:00
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pub_type： 杂志文章
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更新日期：2009-09-01 00:00:00
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pub_type： 杂志文章
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pub_type： 杂志文章
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更新日期：1991-10-01 00:00:00
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journal_title：Molecular and cellular biology
pub_type： 杂志文章
doi：10.1128/mcb.9.10.4531
更新日期：1989-10-01 00:00:00
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更新日期：1989-02-01 00:00:00
