Effects of DNA Mutations on Protein Sequences
Consider the phrase MDNAISTHEGENETICMATERIAL*. M is the beginning, for Methionine, known as the initiation codon in an mRNA sequence, and * is the stop codon.[more]
The DNA sequence of a structural gene determines the mRNA sequence, and subsequently, the protein sequence. In this Demonstration, a DNA sequence was generated that, when translated using the standard single letter code for the amino acids, yields the given phrase. Removing the starting M and ending * and adding convenient spaces gives us an "English" message from the DNA code.
Mutations in the DNA sequence can produce changes in the protein sequence by altering one or more 3 bp (base pair) codons. Select from three different mutation types: single bp substitution (e.g. A, C, or T for G), single bp insertion, or single bp deletion.
The starting "wild type" DNA sequence is shown in the first row with its translation in the second row. The third row shows the mutagenized sequence with the altered codon triplet highlighted in pink. The fourth row shows the changes in the protein sequence highlighted in light blue. Mutations affecting the ATG (AUG in the mRNA) start codon prevent translation. The "English" output of the translation is shown below the grid.
Click "mutate" and select a "mutation" type to generate different mutations and observe their effects.[less]