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Evolution of prokaryotic genes by shift of stop codons
Anna A Vakhrusheva1, Marat D Kazanov, Andrey A Mironov
1Department of Bioengineering and Bioinformatics, M.V. Lomonosov Moscow State University, Vorbyevy Gory 1-73, Moscow 119992, Russia.
Journal of Molecular Evolution
|November 18, 2010
Summary
Stop codon shifts in prokaryotes alter gene length by adding 3' untranslated regions or subtracting coding segments. This mechanism, driven by mutations, contributes significantly to functional evolution of gene length.
Area of Science:
- Molecular Biology
- Evolutionary Biology
- Genomics
Background:
- The de novo origin of coding sequences is poorly understood.
- Stop codon shifts, caused by mutations or frameshifts, can alter gene length by changing translation termination.
- Understanding these shifts is crucial for molecular evolution studies.
Purpose of the Study:
- To investigate the evolution of prokaryotic gene length through stop codon position changes.
- To identify mechanisms of coding sequence addition and subtraction via stop codon shifts.
- To assess the significance of stop codon shifts in prokaryotic functional evolution.
Main Methods:
- Analysis of prokaryotic gene sequences to detect stop codon shifts.
- Identification of mutations (substitutions, indels) affecting stop codons.
- Comparison of amino acid composition in altered gene regions.
- Distinguishing biological shifts from sequencing errors or rare variants.
Main Results:
- Observed addition of 3' untranslated regions (3'UTR) to genes due to stop codon mutations.
- Documented subtraction of C-terminal coding segments via nonsense mutations.
- Found that many shifts are not attributable to errors or rare variants.
- Identified facilitated additions and nearby stop codons for subtractions.
- Noted biased amino acid composition in added regions.
Conclusions:
- Stop codon shifts are an underappreciated mechanism driving gene length evolution in prokaryotes.
- These shifts contribute to functional adaptation and evolution of genes.
- Mutations altering stop codon position play a key role in prokaryotic molecular evolution.
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