Phylogenetic tree of the proteins encoded by the family of sigN genes. The predicted amino acid sequences encoded by 96 genes that showed significant similarity to sigN1 were compared using the ClutalW program at the online Biology WorkBench facilities from San Diego Supercomputer Center. The alignment was used to construct a phylogenetic tree using the neighbor-joining method and 100 bootstrap trials. The number of times each branch was obtained is indicated. The number assigned to each sigN gene is shown to the right. Group 1 and Group 2 sigN genes are indicated by brackets.