Research

A genetic code alteration generates a proteome of high diversity in the human pathogen Candida albicans

Ana C Gomes¹ , Isabel Miranda¹ , Raquel M Silva¹ , Gabriela R Moura¹ , Benjamin Thomas² , Alexandre Akoulitchev² and Manuel AS Santos¹

¹  CESAM & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal

²  Central Proteomics Facility, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK

author email corresponding author email

Genome Biology 2007, 8:R206doi:10.1186/gb-2007-8-10-r206

Published:	4 October 2007

Subject areas: Molecular biology, Genetics, Evolution, Genome studies

Abstract

Background

Genetic code alterations have been reported in mitochondrial, prokaryotic, and eukaryotic cytoplasmic translation systems, but their evolution and how organisms cope and survive such dramatic genetic events are not understood.

Results

Here we used an unusual decoding of leucine CUG codons as serine in the main human fungal pathogen Candida albicans to elucidate the global impact of genetic code alterations on the proteome. We show that C. albicans decodes CUG codons ambiguously and tolerates partial reversion of their identity from serine back to leucine on a genome-wide scale.

Conclusion

Such codon ambiguity expands the proteome of this human pathogen exponentially and is used to generate important phenotypic diversity. This study highlights novel features of C. albicans biology and unanticipated roles for codon ambiguity in the evolution of the genetic code.