Figure 6.

Phylogenetic analysis of heme nitric oxide binding (H-NOB) domain.This phylogeny was created using the H-NOB domain from the soluble guanylyl cyclases in Figure 5 and a number of bacterial sequences containing the H-NOB domain. Bootstrap supports are shown for select nodes. In agreement with [22] the cyanobacteria (Nostoc and Anabaend) are inferred to be ancestral to all animal guanylyl cyclases (88% bootstrap support).