{
  "id": 4683606,
  "title": "Identification and structural basis of a Chloroflexus protein with homology to Bacillus quorum sensing-related prenyltransferase",
  "url": "https://urgent.news/2026/08/31/identification-and-structural-basis-of-a-chloroflexus-protein-with",
  "topic": "science",
  "section": "Science",
  "published": "2026-08-31T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.08.29.745113v1?rss=1"
  },
  "original_language": "en",
  "account": "Quorum sensing in Gram-positive bacteria typically involves posttranslationally modified peptide pheromones. One such mechanism involves the prenyltransferase ComQ from Bacillus subtilis, which catalyzes tryptophan prenylation of the quorum-sensing peptide ComX. However, the structural basis for this unique modification has not been well understood. In this study, researchers identified a related enzyme, StheQ from Sphaerobacter thermophilus, along with its cognate peptide substrate, StheX. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), they confirmed that StheQ catalyzes prenylation of a specific tryptophan residue in StheX. X-ray crystallography revealed that StheQ adopts the helical fold typical of the trans-isoprenyl diphosphate synthase (IPPS) superfamily, but with an active site adapted specifically for peptide-based indole prenylation. The structures also showed a single magnesium-binding site near the first aspartic acid-rich region, with no evidence of metal coordination at the second aspartic acid-rich motif. Through site-directed mutagenesis, complex formation assays, and docking analyses, the team identified a peptide-binding pocket near the active site, suggesting that residue N215 plays a crucial role in positioning the tryptophan acceptor. These findings clarify the structural basis of peptide prenylation by a ComQ-family enzyme, shedding light on the evolution of peptide-based indole prenylation within the IPPS superfamily, and highlighting that ComQ-family enzymes form a distinct functional branch specialized for this peptide modification.",
  "summary": "Quorum sensing in Gram-positive bacteria commonly relies on posttranslationally modified peptide pheromones. In Bacillus subtilis, the prenyltransferase ComQ catalyzes tryptophan prenylation of the quorum-sensing peptide ComX, but the structural basis of this unique peptide modification has remained unclear. Here we identified a previously uncharacterized ComQ homolog, StheQ, and its cognate…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}