Molecular biology. New way found to study closely related proteins

Rather than designing specific inhibitors for closely related proteins, researchers are remodeling the proteins to make them uniquely susceptible to inhibition. As described in the 21 September issue of Nature, the technique involves enlarging the active site of an enzyme so that it can bind an inhibitor that won't fit into the active sites of related--but unaltered--enzymes. Researchers can then insert the gene that encodes the modified enzyme into cells or living animals and turn off that enzyme by feeding them the inhibitor--without affecting other, very similar, enzymes. The technique may have some advantages over other approaches to studying the functions of individual proteins, such as mutating or knocking out the genes that encode them, which may disrupt embryonic development, producing abnormal animals or no animals at all.     

Molecular biology. Creation's seventh day

Scientists at the Scripps Research Institute are attempting to find out what life would look like if DNA contained more than four nucleotide bases and proteins more than 20 amino acids. By reengineering DNA, RNA, and the proteins that interact with them, they hope to create synthetic organisms with a chemical makeup fundamentally different from all life that has existed on Earth for the last 3.8 billion years. If they succeed, their biochemical reengineering could have a profound effect on everything from basic molecular biology to industrial chemistry.