Analysis of Genomic G + C Content, Codon Usage, Initiator Codon Context and Translation Termination Sites in Tetrahymena thermophila

Document Type

Article

Language

eng

Format of Original

9 p.

Publication Date

5-1999

Publisher

International Society of Protistologists

Source Publication

Journal of Eukaryotic Microbiology

Source ISSN

1066-5234

Abstract

In recent years, the amount of molecular sequencing data from Tetrahymena thermophila has dramatically increased. We analyzed G + C content, codon usage, initiator codon context and stop codon sites in the extremely A + T rich genome of this ciliate. Average G + C content was 38% for protein coding regions. 21% for 5′ non-coding sequences, 19% for 3′ non-coding sequences, 15% for introns, 19% for micronuclear limited sequences and 17% for macronuclear retained sequences flanking micronuclear specific regions. the 75 available T. thermophila protein coding sequences favored codons ending in T and, where possible, avoided those with G in the third position. Highly expressed genes were relatively G + C-rich and exhibited an extremely biased pattern of codon usage while developmentally regulated genes were more A + T-rich and showed less codon usage bias. Regions immediately preceding Tetrahymena translation initiator codons were generally A-rich. For the 60 stop codons examined, the frequency of G in the end + 1 site was much higher than expected whereas C never occupied this position.

Comments

Journal of Eukaryotic Microbiology, Vol. 46, No. 3 (May 1999): 239-247. DOI.

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