University of California, Berkeley
Election Year: 2001
Primary Section: 29, Biophysics and Computational Biology
Secondary Section: 21, Biochemistry
Membership Type: Member
I am interested in the proteins that carry out two fundamental processes: the replication of DNA and the transduction of cellular signals. I use X-ray crystallography to determine the structures of these proteins and I then try to figure out how they work. One question my laboratory focuses on is how tyrosine phosphorylation is used as a switch in the processing of information received by animal cells. We determined the structure of the "SH2 domain," a protein module that recognizes phosphorylated tyrosine residues. Important clues to how SH2 domains work have come from our structures of protein switches that are regulated by SH2 domains, including that of the Src tyrosine kinase and the STAT transcription factor. My laboratory has collaborated in determining the structure of the "sliding clamp" protein, which allows the polymerases that replicate DNA to move at very high speed without letting go of DNA. The protein forms a ring that encircles DNA, providing a mobile platform to which the DNA polymerase is attached. We have also analyzed the structure of the "clamp-loader" protein assembly, which uses energy stored in ATP to open the ring-shaped sliding clamps and load them on DNA.