Researchers at the Ohio State University have reportedly identified a new amino acid which has been named Pyrrolysine. This is considered a discovery that is the biological equivalent of physicists finding a new fundamental particle or chemists discovering a new element.
Amino acids are essential components of the human body and other living things. Prior to this, scientists had believed that there were only 21 natural amino acids - the building blocks of proteins. For thirty years after the discovery of the structure of DNA and the unravelling of the genetic code, scientists believed that there were only 20 natural amino acids. Then in 1986, researchers announced the discovery of the 21st amino acid. Finding a 22nd may suggest that even more of these basic biological building blocks may be found using modern genome sequencing techniques.
The newly discovered amino acid is a component of an enzyme found in bacteria and bacteria-like organisms that helps them make methane, a gas found throughout nature. This discovery shall cause researchers to start looking at genetic sequences that they might have thought at first were simply aberrations. Finding the new genetically encoded amino acid should stimulate the search for more amino acids. With so many researchers dissecting so many genomes now, it is reasonable to expect that there might be more to be discovered.
Science Vol. 296, No. 5572