{
  "abstract": "Cobalamin-dependent methionine synthase (MetH) is a highly dynamic enzyme that requires large-scale domain rearrangements to facilitate turnover and reactivation. Despite significant biochemical and structural efforts, a full picture of the conformational changes underlying the transition between MetH turnover and reactivation has remained elusive. Here, we leverage state-of-the-art cryo-electron microscopy (cryo-EM) methods to reanalyze an old dataset and gain new insights into these changes. By utilizing a neural-network particle picker, performing careful classification of particles, and incorporating high-resolution information to determine initial particle orientations, we uncovered and reconstructed a minor population of reactivation-state MetH (~4.5-5 [A] resolution) from a dataset that is dominated by resting-state MetH. This structure represents the first fully intact structure of the enzyme with a physiological cobalamin cofactor bound. These findings highlight the potential for improved cryo-EM methodology to uncover previously hidden details about enzyme function and deepen our understanding of structural ensembles.",
  "abstract_shown": true,
  "affiliations": [
    "Cornell University"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "name": "H. Wang"
    },
    {
      "name": "M. B. Watkins"
    },
    {
      "name": "P. Suksmith"
    },
    {
      "affs": [
        0
      ],
      "name": "N. Ando"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6a93fgx61e1c8.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.07.27.741092",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.07.27.741092v2.full",
  "id": "6a93fgx61e1c8",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.07.27.741092v2",
  "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",
      "1315|Advanced Electron Microscopy Techniques and Applications"
    ]
  ],
  "openalex": "W7171514679",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.07.27.741092v2.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6a93fgx61e1c8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:24Z",
      "native_id": "10.64898/2026.07.27.741092",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.07.27.741092v2"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "openalex:1315|Advanced Electron Microscopy Techniques and Applications",
      "subfield": "structural-biology"
    }
  ],
  "title": "Recovery of a minor cryo-EM particle population reveals conformational equilibria linking cofactor loading, turnover, and reactivation in methionine synthase",
  "title_text": "Recovery of a minor cryo-EM particle population reveals conformational equilibria linking cofactor loading, turnover, and reactivation in methionine synthase",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:24Z",
  "url": "https://research.draconitic.com/paper/6a93fgx61e1c8",
  "venue": "bioRxiv",
  "versions": []
}