Structure of the Bacillus subtilis quorum-sensing peptide pheromone ComX

Abstract

The ComX pheromone is an extracellular signaling molecule that stimulates natural competence in response to crowding in the gram-positive bacterium Bacillus subtilis. The pheromone is formed by isoprenylation of an inactive precursor peptide, but its precise structure is not known. Here we report the structure of the ComX pheromone, showing that addition of a geranyl group to a tryptophan residue results in the formation of an unusual ring structure.

PqqD Is a Novel Peptide Chaperone That Forms a Ternary Complex with the Radical S-Adenosylmethionine Protein PqqE in the Pyrroloquinoline Quinone Biosynthetic Pathway

“…Ribosomally synthesized and post-translationally modified peptides constitute a major class of natural products consisting of bioactive compounds such as antibiotics (1)(2)(3), quorum sensing molecules (4,5), metal chelators (6), and redox cofactors (7). Certain ribosomally derived products rely on radical S-adenosylmethionine enzymes (herein referred to as RS proteins) to catalyze the formation of ␣-carbon thioether bonds or carbon-carbon bonds (8,9).…”

Bacterial Biofilms: A Confrontation to Medical Science

“…The formation process of biofilm is extremely complex, in which Microorganism cells transform from plank tonic to sessile mode of growth. It has also been insinuated that the formation of biofilm depends upon the expression of specific genes that directs the constitution of biofilm [11,12]. A fully developed biofilm is composed of many layers comprising a matrix of exopolysaccharide with vertical structures, and a conditioning film.…”

Post-Translational Isoprenylation of Tryptophan

“…[23][24][25][26] Also, the ComX RO-C-2 pheromone from B. mojavensis strain RO-C-2 has been confirmed to have a farnesyl-modified tryptophan residue similar to that of the ComX RO-E-2 pheromone. 27) Together with its phylogenetic resemblance to ComX, these findings suggest that post-translational isoprenoidal modifications of ComX pheromones can be classified into two types: geranyl and farnesyl (Fig.…”

“…4). [23][24][25][26][27][28] For instance, the ComX 168 pheromone, produced by standard B. subtilis strain 168, is also modified with a farnesyl group, similarly to that of the ComX RO-C-2…”