Department of Chemistry and Biochemistry, UCLA-DOE Center for Genomics and Proteomics, Molecular Biology Institute, Boyer Hall, UCLA, 611 Charles E. Young Drive E, Los Angeles, California 90095-1570, USA. bowie@mbi.ucla.edu
One of the great challenges for molecular biologists is to learn how a protein sequence defines its three-dimensional structure. For many years, the problem was even more difficult for membrane proteins because so little was known about what they looked like. The situation has improved markedly in recent years, and we now know over 90 unique structures. Our enhanced view of the structure universe, combined with an increasingly quantitative understanding of fold determination, engenders optimism that a solution to the folding problem for membrane proteins can be achieved.