{
  "abstract": "Bifunctional glycosyltransferases underpin biosynthesis of essential glycans, including bacterial capsular antigens, and eukaryotic glycosaminoglycans. Typically, these enzymes transfer hexose sugars from activated nucleotide-phosphate donors, forming new glycosidic bonds with either retention or inversion of anomeric stereochemistry. Retaining hexosyl transfer typically proceeds via non-covalent SNi-type pathways, but recent studies of octulosyl Kdo-transferases have reignited debate over covalent mechanisms. Here we comprehensively dissected the activity of the archetypal bifunctional glycosyltransferase PmHS2, providing X-ray structures of ligand complexes alongside atomistic simulations to delineate full substrate-to-product reaction trajectories. Combined computational, biochemical and evolutionary evidence suggests that PmHS2 retaining GlcNAc-transfer likely proceeds via a previously undescribed covalent mechanism, involving considerable assistance from departing nucleotide-phosphate rotation. In mapping reaction pathways, we also report the first example of a glycosyl donor substrate coopted as an acceptor, which enables enzymatic self-priming for polymerization. These new covalent and self-priming functionalities highlight unexplored routes to modulate or inhibit polysaccharide biosynthesis.",
  "abstract_shown": true,
  "affiliations": [
    "Rosalind Franklin Institute"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 11,
  "authors": [
    {
      "name": "M. Sagiroglugil"
    },
    {
      "name": "B. P. Castillo"
    },
    {
      "name": "M. A. Leanca"
    },
    {
      "name": "E. S. Kitano"
    },
    {
      "name": "C. J. Mycroft-West"
    },
    {
      "name": "G. Papadakis"
    },
    {
      "name": "M. A. Gafitescu"
    },
    {
      "name": "S. Mohammed"
    },
    {
      "name": "B. G. Davis"
    },
    {
      "name": "C. Rovira"
    },
    {
      "affs": [
        0
      ],
      "name": "L. Wu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cry55t8m95bad.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.10.20.760405",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.10.20.760405v1.full",
  "id": "cry55t8m95bad",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.10.20.760405v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "biochemistry"
    ],
    [
      "openalex",
      "1605|Carbohydrate Chemistry and Synthesis"
    ]
  ],
  "openalex": "W7223150547",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.10.20.760405v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cry55t8m95bad.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:28:54Z",
      "native_id": "10.64898/2026.10.20.760405",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.10.20.760405v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1605|Carbohydrate Chemistry and Synthesis",
      "subfield": "organic"
    }
  ],
  "title": "Hexosyl transfer via a covalent intermediate within a dual retaining and inverting enzyme",
  "title_text": "Hexosyl transfer via a covalent intermediate within a dual retaining and inverting enzyme",
  "type": "preprint",
  "updated_at": "2026-10-30T12:28:54Z",
  "url": "https://research.draconitic.com/paper/cry55t8m95bad",
  "venue": "bioRxiv",
  "versions": []
}