Small proteins also promise to revise the current understanding of the genome. Many appear to be encoded in stretches of DNA—and RNA—that were not thought to help build proteins of any sort. Some researchers speculate that the short stretches of DNA could be newborn genes, on their way to evolving into larger genes that make full-size proteins. Thanks in part to small proteins, “We need to rethink what genes are,” says microbiologist and molecular biologist Gisela Storz of the National Institute of Child Health and Human Development in Bethesda, Maryland.
Tiny proteins help power muscles and provide the toxic punch to many venoms.