Organism Can Produce 10 Trillion Proteins

Biochemists have identified an organism that can produce 10 million million varieties of one protein. Bacteria mutate swiftly, changing their protein coats, which is why antibiotics become less effective with time. Bacteriophages, which latch on to proteins in bacteria, should have the same problem. But Stephen McMahon and colleagues at the University of California San Diego report in Nature Structural and Molecular Biology that by altering its own search-and-infect protein, laboratory phage can generate 10 trillion proteins, each of which could stick to a potential protein on a bacterium.