ARAMEMNON is a curated database for Arabidopsis thaliana transmembrane (TM) proteins and transporters. The database compiles topology and signal sequence predictions and displays the results in a directly comparable graphical output format for presently 7139 genes/proteins. The reliability of TM prediction is improved by calculating a consensus TM prediction. ARAMEMNON also contains experimental intracellular localization data from the literature, a comprehensive bibliography and many other features for data mining and sequence interpretation of Arabidopsis membrane proteins. ARAMEMNON is accessible at the URL http://aramemnon.botanik.uni-koeln.de.