Figure 6From: Is the C-terminal insertional signal in Gram-negative bacterial outer membrane proteins species-specific or not?Frequency of His at the +3 position. The percentage of His at +3 was calculated from all unique peptides from 437 organisms. A high preference for His at +3 is observed for 16-stranded OMPs of β-Proteobacteria. Since there is a high number of 16-stranded OMPs in Burkholderia strains (see Additional file1 and Additional file2), they were also annotated in the plot.Back to article page