兄弟同心：微生物免疫系统的古老起源

Key human defenses against pathogens were forged billions of years ago in microbial battles with viruses RICHARD STONE When Philip Kranzusch puzzled out the structure of an enzyme from the cholera bacterium in 2013, the biochemist got a jolt. The folds, the ac- tive site, the overall architecture were unmistak- able: This was a bacterial cousin of a human protein that acts as a sentry for invading viruses. “A lightning bolt ran through my mind,” says Kranzusch, then a young postdoc in the laboratory of structural biologist Jennifer Doudna at the University of California (UC), Berkeley. “Immune pro- teins in human cells could be far more ancient than we’d thought.” Bernheim, a microbiologist at the Pasteur Institute. …