Skip Navigation

This Article
Right arrow Full Text Freely available
Right arrow Print PDF (420K) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Right arrow Commercial Re-use Guidelines
for Open Access NAR Content
Google Scholar
Right arrow Articles by Greenwood, S. J.
Right arrow Articles by Gray, M. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Greenwood, S. J.
Right arrow Articles by Gray, M. W.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Nucleic Acids Research, 2001, Vol. 29, No. 10 2191-2198
© 2001 Oxford University Press

Analysis of intergenic spacer transcripts suggests ‘read-around’ transcription of the extrachromosomal circular rDNA in Euglena gracilis

Spencer J. Greenwood, Murray N. Schnare, James R. Cook1 and Michael W. Gray*

Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada and 1Department of Zoology, University of Maine, Orono, ME 04469, USA

We report here the sequence of the 1743 bp intergenic spacer (IGS) that separates the 3'-end of the large subunit ribosomal RNA (rRNA) gene from the 5'-end of the small subunit (SSU) rRNA gene in the circular, extrachromosomal ribosomal DNA (rDNA) of Euglena gracilis. The IGS contains a 277 nt stretch of sequence that is related to a sequence found in ITS 1, an internal transcribed spacer between the SSU and 5.8S rRNA genes. Primer extension analysis of IGS transcripts identified three abundant reverse transcriptase stops that may be analogous to the transcription initiation site (TIS) and two processing sites (A' and A0) that are found in this region in other eukaryotes. Features that could influence processing at these sites include an imperfect palindrome near site A0 and a sequence near site A' that could potentially base pair with U3 small nucleolar RNA. Our identification of the TIS (verified by mung bean nuclease analysis) is considered tentative because we also detected low-abundance transcripts upstream of this site throughout the entire IGS. This result suggests the possibility of ‘read-around’ transcription, i.e. transcription that proceeds multiple times around the rDNA circle without termination.

* To whom correspondence should be addressed. Tel: +1 902 494 2521; Fax: +1 902 494 1355; Email: m.w.gray{at}dal.ca Present address: Spencer J. Greenwood, Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada. James R. Cook, deceased.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 RNAHome page
A. G. RUSSELL, M. N. SCHNARE, and M. W. GRAY
Pseudouridine-guide RNAs and other Cbf5p-associated RNAs in Euglena gracilis
RNA, July 1, 2004; 10(7): 1034 - 1046.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.