Chemistry of microbial signal compounds

Abstract

The ComX pheromone is a post-translationally modified oligopeptide that stimulates natural genetic competence controlled by quorum sensing in Bacillus subtilis. The structure of the ComX_RO-E-2 pheromone produced by strain RO-E-2 was determined. In the pheromone molecule, a geranyl group is bound to the tryptophan residue, which results in the formation of a tricyclic ring structure. Molds in the genus Phytophthora are some of the most destructive phytopathogens known. An important biological event in Phytophthora is sexual reproduction. A factor known as hormone α1 is secreted by the A1 mating type, and this induces the formation of oospores in the A2 mating type. The structure of hormone α1 is a C-20 linear isoprenoid and the absolute stereochemistry was determined by chemical synthesis.