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dc.contributor.authorOommen, Abraham
dc.contributor.authorLi, Xinqiang
dc.contributor.authorGegenheimer, Peter Albert
dc.date.accessioned2015-04-10T16:52:28Z
dc.date.available2015-04-10T16:52:28Z
dc.date.issued1992-02
dc.identifier.citationOommen, A., X. Q. Lli, and Peter Albert Gegenheimer. "Cleavage Specificity of Chloroplast and Nuclear TRNA 3'-processing Nucleases." Molecular and Cellular Biology 12.2 (1992): 865-75. Web. 10 Apr. 2015. http://dx.doi.org/10.1128/MCB.12.2.865.en_US
dc.identifier.urihttp://hdl.handle.net/1808/17376
dc.descriptionThis is the publisher's version. Copyright 2015 by the American Society for Microbiology.en_US
dc.description.abstracttRNAs in eukaryotic nuclei and organelles are synthesized as precursors lacking the 3'-terminal CCA sequence and possessing 5' (leader) and 3' (trailer) extensions. Nucleolytic cleavage of the 3' trailer and addition of CCA are therefore required for formation of functional tRNA 3' termini. Many chloroplast tRNA genes encode a C at position 74 which is not removed during processing but which can be incorporated as the first base of the CCAOH terminus. Sequences downstream of nucleotide 74, however, are always removed. Synthetic yeast pre-tRNA(Phe) substrates containing the complete CCA74-76 sequence were processed with crude or partially purified chloroplast enzyme fractions. The 3'-extended substrates (tRNA-CCA-trailer) were cleaved exclusively between nucleotides 74 and 75 to give tRNA-COH, whereas a 3'-mature transcript (tRNA-CCAOH) was not cleaved at all. A 5'-, 3'-extended chloroplast tRNA-CAG-trailer was also processed entirely to tRNA-COH. Furthermore, a 5'-mature, 3'-extended yeast pre-tRNA(Phe) derivative, tRNA-ACA-trailer, in which C74 was replaced by A, was cleaved precisely after A74. In contrast, we found that a partially purified enzyme fraction (a nuclear/cytoplasmic activity) from wheat embryo cleaved the 3'-extended yeast tRNA(Phe) precursors between nucleotides 73 and 74 to give tRNA(OH). This specificity is consistent with that of all previously characterized nuclear enzyme preparations. We conclude that (i) chloroplast tRNA 3'-processing endonuclease cleaves after nucleotide 74 regardless of the nature of the surrounding sequences; (ii) this specificity differs from that of the plant nuclear/cytoplasmic processing nuclease, which cleaves after base 73; and (iii) since 3'-mature tRNA is not a substrate for either activity, these 3' nucleases must require substrates possessing a 3'-terminal extension that extends past nucleotide 76. This substrate specificity may prevent mature tRNA from counterproductive cleavage by the 3' processing system.en_US
dc.publisherAmerican Society for Microbiologyen_US
dc.titleCleavage specificity of chloroplast and nuclear tRNA 3'-processing nucleases.en_US
dc.typeArticle
kusw.kuauthorGegenheimer, Peter Albert
kusw.kudepartmentMolecular Biosciencesen_US
dc.identifier.doi10.1128/MCB.12.2.865
kusw.oaversionScholarly/refereed, publisher version
kusw.oapolicyThis item does not meet KU Open Access policy criteria.
dc.rights.accessrightsopenAccess


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