Simultaneous Positive and Purifying Selection on Overlapping Reading Frames of the tat and vpr Genes of Simian Immunodeficiency Virus

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Silva Jack da (Creator)

Austin L. Hughes (Creator)

David H. O'Connor (Creator)

David I. Watkins (Creator)

Kristi Westover (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: Tat-specific cytotoxic T cells have previously been shown to exert positive Darwinian selection favoring amino acid replacements of an epitope of simian immunodeficiency virus (SIV). The region of the tat gene encoding this epitope falls within a region of overlap between the tat and vpr reading frames and nonsynonymous nucleotide substitutions in the tat reading frame were found to occur disproportionately in such a way as to cause synonymous changes in the vpr reading frame. Comparison of published complete SIV genomes showed Tat to be the least conserved at the amino acid level of nine proteins encoded by the virus while Vpr was one of the most conserved. Numerous parallel amino acid changes occurred within the Tat epitope independently in different monkeys and purifying selection on the vpr reading frame by limiting acceptable nonsynonymous substitutions in the tat reading frame evidently has enhanced the probability of parallel evolution. Originally published Journal of Virology Vol. 75 No. 17 Sep 2001

Additional Information

Publication

Other

Journal of Virology. 75:17(September 2001) p. 7966-7972.

Language: English

Date: 2011

Keywords

simian immunodeficiency virus, tat gene, epitopes

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