The searchable mutant database tGRAP (previously called tinyGRAP) at the University of Tromsø contains data on mutated G-protein coupled receptors (GPCRs). All data have been extracted from scientific papers and entered manually into the database. The current version of the tGRAP mutant database (tGRAP.uit.no, release 10, April 2001) contains around 10 500 mutants extracted from almost 1400 research papers containing mutant data on five families of GPCRs, i.e. Family A, rhodopsin-like; Family B, secretin-like; Family C, metabotropic glutamate-like; Family D, pheromone; Family E, cAMP receptors. A query form provides rapid and simple access to relevant mutant information. In addition to this query form, a tool that enables the user to access mutation data via sequence alignments has been introduced. The ability to access mutant data from such alignments increases the usefulness of the mutant database and facilitates comparison of mutagenesis data between receptors. Moreover, this tool allows the construction of tailor-made sequence alignment views from any combination of receptors belonging to the same class. The database is available at http://tGRAP.uit.no/.
