FIGURE 6.

Phylogeny of small subunit IPMI and HACN proteins from archaea. The phylogeny was inferred by the protein maximum likelihood method and rooted using the crenarchaeal IPMI/HACN homologs as an out-group. The bootstrap values are shown near branches supported by a plurality of 100 trees inferred by the same method. Only the functions of the MJ1277 (IPMI) and MJ1271 (HACN) proteins have been experimentally confirmed, but related proteins predicted to catalyze each reaction are grouped by braces. The numbers in parentheses differentiate the IPMI and HACN paralogs in each species. The full organism names and sequence accession numbers are listed in the supplemental materials. The scale bar indicates 0.1 amino acid changes expected per site.