{
  "abstract": "Initiator methionine excision is an early step in protein maturation, but where it might influence protein complex assembly remains poorly understood. This study asked which human protein N-terminal positions engage assembly partners and whether their interface environments point to specific roles for methionine removal. A survey of 7,246 deposited human biological assemblies compared 1,123 eligible proteins. N-terminal positions in MetAP-permissive residue-2 classes were less often interface-engaged than those in nonpermissive classes (37.5% versus 47.5%; adjusted odds ratio 0.65). Nevertheless, 261 permissive-class proteins showed substantial engagement in at least one modeled assembly, including 175 candidates retained after filtering for observed terminal boundaries. Partner-resolved comparisons of proteasome subunits PSMA7, PSMA6 and PSMA4 revealed distinct neighboring-subunit, assembly-chaperone and multi-partner environments. Thus, the possible importance of methionine removal depends not only on sequence, but also on which partner an N-terminal position encounters in a particular assembly context. This structural atlas identifies candidates for direct tests of how verified terminal processing affects partner engagement, complex assembly and function.",
  "abstract_shown": true,
  "affiliations": [
    "Saint Louis University Medical School"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Y.-H. Chang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4cbeyd7w2tn0e.bib",
  "cited_by": 1,
  "doi": "10.64898/2026.08.31.748389",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748389v1.full",
  "id": "4cbeyd7w2tn0e",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748389v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "biochemistry"
    ],
    [
      "openalex",
      "2505|Enzyme Structure and Function"
    ]
  ],
  "openalex": "W7204807980",
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748389v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-31",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4cbeyd7w2tn0e.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:49Z",
      "native_id": "10.64898/2026.08.31.748389",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.08.31.748389v2"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Enzyme Structure and Function",
      "subfield": "materials-polymers"
    }
  ],
  "title": "A structural census links penultimate-residue class to N-terminal burial in human protein assemblies",
  "title_text": "A structural census links penultimate-residue class to N-terminal burial in human protein assemblies",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:02Z",
  "url": "https://research.draconitic.com/paper/4cbeyd7w2tn0e",
  "venue": "bioRxiv",
  "versions": []
}