"One of the ""grand challenges"" facing biologists is predicting the complex three-dimensional structure of proteins. The kinks and folds in these large molecules largely determine their behavior; certain combinations of coiled proteins in virus membranes, for example, allow the virus to insinuate itself into a cell. Bonnie Berger is leading a group of computational biologists to develop software that uses mathematical algorithms to predict protein folding based on the sequence of amino acids. Such insights could eventually lead to new drugs to combat viral disease such as AIDS. Her lab is also tackling the problem of gene identification: devising software that can help indicate where in the mind-numbingly vast strings of DNA sequences (most of which are random filler called introns) lie the bits and pieces of actual genes that carry the blueprints for proteins. Berger started out as a computer scientist and applied mathematician. But as an MIT postdoc looking for ways to apply the algorithms she was devising, she found that it was the biologists who gave her some of the most interesting problems. So she took some courses in biochemistry and, she says, ""picked up biology on a need-to-know basis."" Moving from computers and mathematics to biology, she admits, has brought on ""culture shock."" But she is thriving in this mixed milieu. ""Her work has been highly innovative and important,"" says MIT math professor Daniel J. Kleitman--all the more remarkable, he says, because ""it is very unusual for a computer scientist to make a recognized impact in biology."