Fig. 3.

Analysis of IsItABarrelDB by protein type. (A) Distribution of sequence lengths (dashed lines) and barrel lengths (solid lines) of the eleven largest types of TMBBs in the IsItABarrelDB. Number of TMBBs used to calculate sequence and barrel lengths in parenthesis. Maxima of the barrel sizes are labeled. (B) Correlation between barrel size for structurally resolved barrels and barrel size estimated by IsItABarrel using the closing contact feature. (C) Kernel density estimate of the distribution of sequence lengths for structurally resolved (gray) and IsItABarrelDB (black) TMBBs, rug plot showing instances below. (D) C-terminal sequence motifs found by MEME. Logo plots of motifs found in the C terminus of TMBBs for each protein type. The letters at each position are ordered from top to bottom by most common to least common. The height of each letter is proportional to its frequency in the column, while the height of the stack is adjusted to be the information content expressed in bits of the aligned sequences at that particular position. The colors of the letters indicate physicochemical properties: orange–small, magenta–acidic, blue–hydrophobic plus cysteine, cyan–tyrosine, pink–histidine, green–polar, red–basic, yellow–proline. The number of TMBBs used for the search is at top in parenthesis.