Figure 3.

Unrooted relationship tree of His protein kinases and related proteins in Arabidopsis. The tree is branched into three groups: the ethylene receptors, the photoreceptor phytochromes, and the AHK members. The entire amino acid sequences of His protein kinases were aligned by the Clustal X program (Thompson et al., 1997) and the relationship tree was produced by the TreeView program (Page, 1996). The AHK members, the ethylene receptors, and the phytochromes are in light-gray, gray, and dark-gray shade, respectively.