Positional preferences of polypurine/polypyrimidine tracts in saccharomyces cerevisiae genome: implications for cis regulation of gene expression

Raghavan, Sowmya ; Burma, Pradeep K. ; Brahmachari, Samir K. (1997) Positional preferences of polypurine/polypyrimidine tracts in saccharomyces cerevisiae genome: implications for cis regulation of gene expression Journal of Molecular Evolution, 45 (5). pp. 485-498. ISSN 0022-2844

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Official URL: http://www.springerlink.com/content/70fpe0xrabc6ul...

Related URL: http://dx.doi.org/10.1007/PL00006253

Abstract

The complete genome of the baker's yeast S. cerevisiae was analyzed for the presence of polypurine/polypyrimidine (poly[pu/py]) repeats and their occurrences were classified on the basis of their location within and outside open reading frames (ORFs). The analysis reveals that such sequence motifs are present abundantly both in coding as well as noncoding regions. Clear positional preferences are seen when these tracts occur in noncoding regions. These motifs appear to occur predominantly at a unit nucleosomal length both upstream and downstream of ORFs. Moreover, there is a biased distribution of polypurines in the coding strands when these motifs occur within open reading frames. The significance of the biased distribution is discussed with reference to the occurrence of these motifs in other known mRNA sequences and expressed sequence tags. A model for cis regulation of gene expression is proposed based on the ability of these motifs to form an intermolecular triple helix structure when present within the coding region and/or to modulate nucleosome positioning via enhanced histone affinity when present outside coding regions.

Item Type:Article
Source:Copyright of this article belongs to Springer-Verlag.
Keywords:Repetitive sequences; Polypurine/Polypyrimidine; Nucleosome; Triple helix; DNA sequence analysis; S. cerevisiae genome; Gene expression; cis regulation
ID Code:6393
Deposited On:20 Oct 2010 09:18
Last Modified:23 May 2011 06:01

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