Enzymatic synthesis of pyrrolysine, the mysterious 22nd amino acid
Monday, November 21, 2011 - 20:30
in Biology & Nature
With few exceptions, all known proteins are built up from only twenty amino acids. 25 years ago scientists discovered a 21st amino acid, selenocysteine and ten years ago a 22nd, the pyrrolysine. However, how the cell produces the unusual building block remained a mystery. Now researchers have elucidated the structure of an important enzyme in the production of pyrrolysine.