Related Experiment Video
Updated: Mar 21, 2026
07:31
ACT1-CUP1 Assays Determine the Substrate-Specific Sensitivities of Spliceosomal Mutants in Budding Yeast
Published on: June 30, 2022
3.0K
A novel nuclear genetic code alteration in yeasts and the evolution of codon reassignment in eukaryotes
Stefanie Mühlhausen1, Peggy Findeisen1, Uwe Plessmann2
1Group Systems Biology of Motor Proteins, Department of NMR-Based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany;
Genome Research
|May 20, 2016
Summary
The yeast Pachysolen tannophilus reassigns the CUG codon to translate as alanine instead of leucine. This genetic code evolution discovery in yeast offers a new mechanism for nuclear genetic code alterations.
Area of Science:
- Molecular Biology
- Genetics
- Evolutionary Biology
Background:
- The genetic code translates nucleotide sequences into amino acid sequences.
- Changes to sense codons are typically detrimental, but rare codon reassignment events demonstrate code evolution.
- Existing models for nuclear genetic code alteration lack resolution.
Purpose of the Study:
- To investigate a novel sense codon reassignment in the yeast Pachysolen tannophilus.
- To elucidate the mechanism behind this genetic code alteration.
Main Methods:
- Proteomics data generation.
- Transfer RNA (tRNA) sequence comparisons.
- Analysis of tRNA anticodon mutations and recognition sites.
Main Results:
- Pachysolen tannophilus translates CUG codons as alanine, not leucine.
- The yeast possesses an anticodon-mutated tRNA(Ala) (tRNACAG) responsible for CUG decoding.
- A tRNA loss-driven mechanism is proposed for CUG codon reassignment in yeasts.
Conclusions:
- A novel sense codon reassignment (CUG to alanine) was identified in Pachysolen tannophilus.
- The findings support a tRNA loss-driven mechanism for nuclear genetic code evolution.
- This mechanism provides a framework for understanding past and predicting future codon reassignments.
Related Concept Videos
03:06From DNA to Protein
24.3K
The flow of genetic information in cells from DNA to mRNA to protein is described by the central dogma, which states that genes specify the sequence of mRNAs, which in turn specify the sequence of amino acids making up all proteins. The decoding of one molecule to another is performed by specific proteins and RNAs. Because the information stored in DNA is so central to cellular function, it makes intuitive sense that the cell would make mRNA copies of this information for protein synthesis...
24.3K
01:25The Central Dogma
144.3K
Overview
144.3K
01:20The Central Dogma
35.2K
The central dogma explains the flow of genetic information from DNA nucleotides to the amino acid sequence of proteins.
RNA is the Missing Link Between DNA and Proteins
In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is...
RNA is the Missing Link Between DNA and Proteins
In the early 1900s, scientists discovered that DNA stores all the information needed for cellular functions and that proteins perform most of these functions. However, the mechanisms of converting genetic information into functional proteins remained unknown for many years. Initially, it was believed that a single gene is...
35.2K
02:05Gene Evolution - Fast or Slow?
8.3K
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
8.3K
02:08Gene Conversion
10.8K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
10.8K
03:21Genome Size and the Evolution of New Genes
9.4K
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
9.4K