Cluster and alignment of single-domain Kunitz/BPTI proteins in Ixodes scapularis. (A), MB tree for single-domain Kunitz/BPTI proteins in Ixodes scapularis. The length of each branch is proportional to the estimated number of substitutions. Bar denotes 20% substitutions per site. The support values for each group (in MB, NJ, and ML tree) were shown in right panel. "NA" mans that proteins in group1 do not cluster into one clade (the bootstrap values < 50%) in the ML tree of single-domain Kunitz/BPTI proteins in Ixodes scapularis. (Note: the value 50% is cutoff value in the Tree Finder.) (B), Alignment of representing single-domain Kunitz/BPTI proteins in Ixodes scapularis. The alignment only shows the part between the first and sixth cysteine (C1-C6) in Kunitz/BPTI protein. Red boxes indicate different insertions relative to group I. The six conserved cysteines were colored by red. Red circle indicates the position of P1 site. Key residues for serine proteases inhibition and ion channels modulating were highlighted in blue and green, respectively. Positively selected sites in group II and III were colored by yellow.
Dai et al. BMC Evolutionary Biology 2012 12:4 doi:10.1186/1471-2148-12-4