Peter Walter is a German-American molecular biologist and biochemist. He earned a B.S. degree in chemistry from the Free University of Berlin, an M.S. degree in organic chemistry from Vanderbilt University, and a Ph.D. in biochemistry from the Rockefeller University. He is currently Professor and former Chairman of the Department of Biochemistry and Biophysics at the University of California, San Francisco.
During his thesis work in Dr. Günter Blobel's laboratory, Walter purified the proteinaceous members of a macromolecular complex essential for protein translocation into the endoplasmic reticulum and showed that it selectively recognizes nascent secretory proteins in the cytoplasm of eukaryotic cells and targets them to the ER. He subsequently identified a 7S RNA component of the complex which is essential for its function and named the holocomplex the signal recognition particle.