genetic code
cagapakis | February 18, 2010Almost every living thing shares an identical genetic code, with three nucleic acids in an RNA sequence coding for a single amino acid in the translated protein sequence. While there are 64 three-letter RNA sequences, there are only 20 amino acids and degeneracy in the code allows some amino acids to be coded by multiple codons. Chemists and synthetic biologists in the past few years have been working to expand this genetic code, with unnatural nucleotides that can be incorporated into DNA and RNA sequences and unnatural amino acids that can expand the chemical functionality of proteins.…
edyong | January 8, 2009
Living things, from bacteria to humans, depend on a workforce of proteins to carry out essential tasks within their cells. Proteins are chains of amino acids that are strung together according to instructions encoded within that most important of molecules - DNA.
The string of "letters" that make up DNA correspond to chains of amino acids, and they are read in threes, with every combination representing one of many amino acids. Until now, scientists believed that this relationship is unambiguous - within any single genome, every three-letter combination maps to one and only one amino acid.…