Termination sequence requirements vary among genes transcribed by RNA polymerase III

Gunnery, S., Ma, Y., Mathews, M. B. (February 1999) Termination sequence requirements vary among genes transcribed by RNA polymerase III. Journal of Molecular Biology, 286 (3). pp. 745-57. ISSN 0022-2836 (Print)

Abstract

RNA polymerase III (pol III) transcription generally terminates at a run of four or more thymidine (T) residues but some pol III genes contain runs of T residues that are not recognized as termination signals. Here, we investigate the terminal signal requirements that are operative in adenovirus virus-associated (VA) RNA genes. In the Xenopus 5 S RNA gene, efficient termination requires the T residues to be in a G+C-rich sequence context, but a run of five T residues in a G+C-rich context does not cause pol III termination when placed 30 nt downstream of the adenovirus-2 VA RNAI promoter in a VA-Tat chimeric gene. The failure of pol III to recognize this putative termination signal is not due to the chimeric nature of the gene or to the proximity of the signal to the promoter, but to its sequence context. Termination at the VA RNA gene site requires a T-rich sequence and is inhibited by the proximity of G residues, but is insensitive to the presence of A residues. The T-rich sequence need not be uninterrupted, however. In the VA RNA gene of the avian adenovirus, CELO, the first of two tandem termination signals contains an interrupted run of T residues, TTATT, which functions as a terminator with high (although not complete) efficiency. These findings, together with a survey of sequences neighboring the terminal site of other pol III genes, lead to the conclusion that pol III termination signals are more complex than hitherto recognized, and that sequence context requirements differ between members of the class 1 and class 2 families of pol III genes.

Item Type: Paper
Uncontrolled Keywords: Animals Aviadenovirus/genetics Conserved Sequence/genetics DNA Mutational Analysis Dependovirus/genetics Genes, Viral/genetics Kinetics Promoter Regions (Genetics)/genetics RNA Polymerase III/classification/ genetics RNA, Ribosomal, 5S/ genetics RNA, Viral/genetics Research Support, U.S. Gov't, P.H.S. Transcription, Genetic/ genetics Xenopus/genetics
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > transcription
bioinformatics > genomics and proteomics
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > RNA polymerase
organism description > animal > Frog > xenopus
CSHL Authors:
Communities: CSHL labs
Depositing User: Kathleen Darby
Date: 26 February 1999
Date Deposited: 28 Apr 2014 17:39
Last Modified: 30 Apr 2014 17:58
Related URLs:
URI: https://repository.cshl.edu/id/eprint/29795

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