Team:Penn State/Codon Optimization

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Codon Optimization


The genetic code is a degenerate one; there are more 3-part combinations of nucleotides than there are amino acids. The topic of codon optimization-that is, the cell's preference for one codon sequence over another in translation-has been heavily researched in an effort to determine the optimal genetic sequences for an organism. This project looks at the effects of repeated amino acid sequences of varying lengths and codons and their effect on the cell.

Codon Optimization

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Overview | Design | Results

Background

All of the proteins around us, with few exceptions, are made up of 20 fundamental building blocks of life - amino acids. Different arrangements and combinations of these basic building blocks give us the diversity of proteins that we see. Messenger RiboNucleic Acids (mRNA) is in essence a "photocopy" of DNA that codes for a gene. mRNA carry codons, which are groups of three bases that code for a single amino acid. There are 64 possible combinations of codons (4 x 4 x 4 = 64), but these combinations are degenerate, so there can be more than one codon that codes for the same amino acid.

The Problem

We have mentioned how these can be a number of codons that can code for the same Amino Acid, and subsequently, a number of tRNA molecules that can carry a given Amino Acid. In nature, and in many organisms, only a select few of these tRNA and codon combinations are used instead of all sequences that code for the same amino acid. This is called codon bias.

The Objective

Our goal for this project is to see which codons are preferred, or biased. We also want to investigate if this bias can change over time, different circumstances, or stresses.