BACKGROUND: Recognition of relevant sequence deviations can be valuable for elucidating functional differences between protein subfamilies. Interesting residues at highly conserved positions can then be mutated and experimentally analyzed. However, identification of such sites is tedious because automated approaches are scarce. RESULTS: Subfamily logos visualize subfamily-specific sequence deviations. The display is similar to classical sequence logos but extends into the negative range. Positive, upright characters correspond to residues which are characteristic for the subfamily, negative, upside-down characters to residues typical for the remaining sequences. The symbol height is adjusted to the information content of the alignment position. Residues which are conserved throughout do not appear. CONCLUSION: Subfamily logos provide an intuitive display of relevant sequence deviations. The method has proven to be valid using a set of 135 aligned aquaporin sequences in which established subfamily-specific positions were readily identified by the algorithm.

UNLABELLED: T(E)Xtopo is a LAT(E)X2epsilon macro package for plotting topology data directly from PHD predictions or SwissProt database files in publication-ready quality. The plot can be shaded automatically to emphasize conserved residues or functional properties of the residue sidechains. The addition of rich decorations, such as labels, annotations and legends, is easily accomplished. AVAILABILITY: The T(E)Xtopo macro package and a full on-line documentation are freely available at http://homepages.uni-tuebingen.de/beitz/ CONTACT: [email protected]

MOTIVATION: Typesetting, shading and labeling of nucleotide and peptide alignments using standard word processing or graphics software is time consuming. Available automatic sequence shading programs usually do not allow manual application of additional shadings or labels. Hence, a flexible alignment shading package was designed for both calculated and manual shading, using the macro language of the scientific typesetting software LATEX2 epsilon. RESULTS: TEXshade is the first TEX-based alignment shading software featuring, in addition to standard identity and similarity shading, special modes for the display of functional aspects such as charge, hydropathy or solvent accessibility. A plenitude of commands for manual shading, graphical labels, re-arrangements of the sequence order, numbering, legends etc. is implemented. Further, TEXshade allows the inclusion and display of secondary structure predictions in the DSSP-, STRIDE- and PHD-format. AVAILABILITY: From http://homepages.uni-tuebingen.de/beitz/tse.h tml (macro package and on-line documentation) CONTACT: [email protected]