Researchers recently announced the first systematic laboratory-induced mutation of successive amino acids in a nearly complete simple bacterial protein. The results demonstrated how protein chemistry and structure, in even the most simple of life’s proteins, are irreducibly complex. The research also showed how the random processes ascribed to genetic mutations are unable to propel favorable evolutionary progress that could lead to new selectable traits.You can read the rest of "Engineered Protein 'Evolution' Proves Biological Complexity", here.
Proteins are chains of amino acids that are coded by the information contained in DNA. Three successive nucleotide bases of DNA code for a single amino acid of a protein, and cells use 20 different amino acids. The specific order of amino acids is required, not only for basic protein functionality, but also for optimized functionality.
In this study, researchers successively changed the DNA code of a bacterial gene to individually mutate every amino acid in a simple bacterial protein of 83 amino acids in length. They then tested the ability of that protein to interact with its target chemical—a ligand, which is a binding molecule in the cell. The section of protein that interacts with a ligand is called the “active site.” The researchers also tested the ability of successively mutated amino acids in the active site of the protein to bind to an artificial substrate.