Summary: Web-based servers implementing the DAS-TMfilter algorithm have been launched at three mirror sites and their usage is described. The underlying computer program is an upgraded and modified version of the DAS-prediction method. The new server is designed to make distinction between protein sequences with and without transmembrane (TM) helices at a reasonably low rate of false positive prediction (∼1 among 100 unrelated queries) while the high efficiency of the original algorithm locating TM segments in queries is preserved (sensitivity of ∼95% among documented proteins with helical TM regions).

Availability: The server operates at three mirror sites: http://mendel.imp.univie.ac.at/sat/DAS/DAS.html, http://wooster.bip.bham.ac.uk/DAS.html and http://www.enzim.hu/DAS/DAS.html. The program is available on request.

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Author notes

1Agricultural Biotechnology Center, Szent-Gyorgyi A. 4, Gödöllö, H-2100 Hungary, 2IMP Bioinformatics, Dr Bohr-Gasse 7, Vienna, A-1030 Austria and 3Institute of Enzymology, Biological Research Center Hungarian Academy of Sciences, H-1518 Budapest P.O. Box 7, Hungary