{
  "abstract": "Cobalamin is a complex yet essential cobalt-containing cofactor synthesized exclusively by prokaryotes and archaea. Aerobic cobalamin biosynthesis requires the CobNST multi-subunit class I cobaltochelatase for cobalt incorporation. Cobalt chelation is dependent on the energy transfer from the CobST AAA+/VWA motor unit to the substrate-binding catalytic unit (CobN). However, the mechanism for assembly and function of CobNST cobaltochelatase remains poorly understood. Here, we used cryo-EM to solve the structures of the AAA+ motor CobS, in the absence and presence of ATP and its VWA-partner protein CobT. Our data reveal that the AAA+ CobS assembles into various conformations, including hexameric planar rings and different spiral left-handed assemblies: hexamers, double rings and filaments. In the absence of nucleotide, the CobT N-terminal domain interacts with CobS left-handed oligomers, remaining in a half-assembled, nonfunctional motor unit. In the CobST complex, ATP induces conformational rearrangement of CobS from left-handed helical oligomers to a right-handed closed hexamer. The simultaneous repositioning of the CobT VWA domain to the AAA+ central pore shifts the motor unit to a functional state, ready-to-drive CobN-catalyzed chelation reaction. These findings define the mechanism for assembly and activation of the class I cobaltochelatase CobST motor.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Biology/Chemistry - Structural Biology of Photosynthetic Microorganisms, University of Osnabrueck, Osnabrueck 49076, Germany"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "name": "A. C. Moura"
    },
    {
      "name": "B. Wiseman"
    },
    {
      "name": "E. Bozkurt"
    },
    {
      "name": "E. Deery"
    },
    {
      "name": "R. W. Pickersgill"
    },
    {
      "name": "A. A. Brindley"
    },
    {
      "name": "A. Hitchcock"
    },
    {
      "name": "M. Hoegbom"
    },
    {
      "name": "M. J. Warren"
    },
    {
      "affs": [
        0
      ],
      "name": "D. Shvarev"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cjw8n1jmmwqzm.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.10.09.757910",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.10.09.757910v1.full",
  "id": "cjw8n1jmmwqzm",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.10.09.757910v1",
  "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",
      "2505|Enzyme Structure and Function"
    ]
  ],
  "openalex": "W7221554751",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.10.09.757910v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cjw8n1jmmwqzm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:22Z",
      "native_id": "10.64898/2026.10.09.757910",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.10.09.757910v2"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Enzyme Structure and Function",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Assembly and activation of the AAA+ motor of the multi-subunit cobaltochelatase",
  "title_text": "Assembly and activation of the AAA+ motor of the multi-subunit cobaltochelatase",
  "type": "preprint",
  "updated_at": "2026-10-30T12:28:06Z",
  "url": "https://research.draconitic.com/paper/cjw8n1jmmwqzm",
  "venue": "bioRxiv",
  "versions": []
}