The PSIPRED protein structure prediction server allows users to submit a protein sequence, perform a prediction of their choice and receive the results of the prediction both textually via e-mail and graphically via the web. The user may select one of three prediction methods to apply to their sequence: PSIPRED, a highly accurate secondary structure prediction method, MEMSAT 2, a new version of a widely used transmembrane topology prediction method, or GenTHREADER, a sequence profile based fold recognition method.