Figure 5. Conservation of functional domains and modes of selection acting on plant SK homologs.

Stacked histograms indicate posterior probabilities of purifying (black), neutral (white), and positive selection (hatched) for sites aligning with key SK catalytic and substrate binding domains indexed to sequence logos for MAFFT amino acid alignments of the plant SK, SKL1, and SKL2 families. * indicates SK residues directly involved in substrate interactions as determined from microbial SK crystallographic structures (see Table 3). The distal arginine of the SK SBD is not shown.