{
  "id": 3427999,
  "title": "Site-specific processing of phosphoethanolamine cellulose by the BcsZ cellulase reveals stochastic biofilm cellulose modification",
  "url": "https://urgent.news/2026/08/25/site-specific-processing-of-phosphoethanolamine-cellulose-by-the-bcsz",
  "topic": "science",
  "section": "Science",
  "published": "2026-08-25T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.08.24.745826v1?rss=1"
  },
  "original_language": "en",
  "account": "Bacterial biofilms consist of cellulose, interacting with other biopolymers to create a three-dimensional matrix enclosing bacteria. The cellulose's surface exposure relies on the presence of the periplasmic cellulase BcsZ. The periplasmic modification of cellulose with lipid-derived phosphoethanolamine (pEtN) in E. coli and Enterobacteriaceae is unclear, including BcsZ's role in hydrolyzing pEtN-cellulose within the periplasm. To investigate, researchers employed carbohydrate synthesis, X-ray crystallography, native mass spectrometry, and super-resolution MINFLUX nanoscopy. The crystal structures of BcsZ bound to chemically synthesized pEtN cello-oligosaccharides illustrate how the enzyme recognizes pEtN-modified glucosyl units. By examining mono and double-substituted cellohexaoses, they identified varying binding poses determined by two pEtN coordination sites within the BcsZ catalytic pocket. These analyses suggest an ideal BcsZ cellohexaose ligand, containing two pEtN-modified units separated by an unmodified cellotriosyl unit. BcsZ exhibits a higher affinity and efficiency when binding and hydrolyzing this compound. Moreover, BcsZ digestion of native pEtN cellulose, combined with native mass spectrometry findings, reveals the stochastic distribution of pEtN on biofilm cellulose. MINFLUX co-localization data with other biosynthetic complex components suggests BcsZ functions independently within the periplasm to eliminate mislocalized pEtN cellulose.",
  "summary": "Cellulose is a common component of bacterial biofilms where it interacts with other biopolymers to form a 3-dimensional matrix enclosing the bacteria. Synthesized and secreted by the synthase-dependent biosynthesis pathway common to many bacterial exopolysaccharides, its surface exposure depends on the presence of the periplasmic cellulase BcsZ. During export across the periplasm, E. coli and…",
  "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."
}