FIG. 3.

MP tree constructed with the program PROTPARS from the 492 amino acid positions marked by + in Fig. 1. Numbers on internal branches are BCL based on 100 bootstrap replications of the original alignment. Only BCL of >30% are shown. Branch lengths do not represent number of steps. Abbreviations: NS, nonsulfur; mt, mitochondria; chl, chloroplasts. Archaeal sequences are boxed; asterisks indicate the two new sequences reported here. For full organism names, see the legend to Fig. 2.