FIG. 3.

Clustering of cyanobacterial sesquiterpene synthase ORFs from Nostoc and Anabaena with ORFs encoding a cytochrome P450 and a putative hybrid two-component protein. ORFs flanking the terpene synthase mini-gene cluster differ in the three cyanobacterial genomes, suggesting functional significance of the gene cluster. The lower panel shows the different domains identified in the putative hybrid two-component protein by searching the NCBI conserved domain database. The GAF domain acronym derives from the names of the first three protein classes identified to contain this domain: mammalian cGMP-stimulated phosphodiesterases, Anabaena adenylyl cyclases, and E. coli transcription factor FhlA.