Phylogenetic relationships of the IQ67 domains encoded by IQD genes from Arabidopsis thaliana, Oryza sativa, Pinus ssp. and Physcomitrella patens. The unrooted tree was constructed from the alignment shown in Figure 2 using PAUP* 4.0 and the neighbor-joining method. Numbers on branches indicate the percentage of 1000 bootstrap replicates that support the adjacent node; low bootstrap support (<50%) was not reported. Black braces and Arabic numerals at right indicate the three major subfamilies as defined by the phylogenetic analysis of the 72 IQ67 domain sequences. Gene identification and accession numbers are colored using the same code as in Figure 6 to denote the different subfamilies of the parental IQD proteins. Accession numbers of the putative pine and moss IQD proteins are given the prefixes 'Ps' and 'Pp', respectively. The asterisk denotes the putative rice IQD protein for which a full-length amino acid sequence could not be predicted (see Table 2).