E signature sequences in different proteins support the division of Archaebacteria into two distinct groups (Euryarchaeota and Crenarchaeota) and of gram-positive bacteria into at least two groups, corresponding to the low-G C and high-G C species, of which the high-G C group is specifically related to the diderm prokaryotes. The DeinococcusThermus group of species appears to be intermediate in th
Sp70 (Fig. 26) and Hsp90 (Fig. 31) also contain several unique sequence signatures not found in any prokaryotic homologs. These signature provides evidence that all of the eukaryotes are derived from a single ancestor and that the postulated fusion event was unique.VOL. 62,PHYLOGENY OF PROKARYOTES AND EUKARYOTEScluding amitochondriate and aplastidic cells, received major gene contributions to the