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TMAP application details page
Displays membrane spanning regions
This program predicts transmembrane segments in proteins, utilising the algorithm described in: "Persson, B. & Argos, P. (1994) Prediction of transmembrane segments in proteins utilising multiple sequence alignments J. Mol. Biol. 237, 182-192." tmap reads in one or more aligned protein sequences. Two sets of propensity values are then used for the calculations: onefor the middle, hydrophobic portion and one for the terminal regions ofthe transmembrane sequence spans. Average propensity values arecalculated for each position along the alignment, with the contributionfrom each sequence weighted according to its dissimilarity relative tothe other aligned sequences. Eight-residue segments are considered as potential cores oftransmembrane segments and elongated if thier middle propensity valuesare above a threshold. End propensity values are also considered asstop signals. Only helices with a length of 15 to 29 residues areallowed and corrections for strictly conserved charged residues aremade. The method is more successful than predictions based upon singlesequences alone. The results are plotted on a graph and written to a text file.
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