{
  "abstract": "The deamination of guanosine nucleobases results in the formation of xanthosine (X)-containing RNA. This process formally resembles adenine deamination (A-to-I editing). The biological significance and basic chemical consequences of X-modified RNA are poorly understood. In this study, we examine xanthosine interactions with tailored pyrimidine nucleobases. We synthesized RNAs that provide either the 2,4-diaminopyrimidine C-nucleoside kappa (K) or 2-iminocytidine (2imC) as an \"ideal\" tridendate Watson-Crick pairing partner. For K-modified RNA, we used a phosphoramidite previously introduced for RNA solidphase synthesis. For 2imC-modified RNA, we developed access via synthetic 2-thiocytidine (2sC)-modified RNA, followed by osmium tetroxide (OsO 4 )-ammonium chloride (NH 4 Cl)-mediated transformation into 2imC-modified RNA. RNAs with K-X or 2imC-X base pairs indeed showed stable duplex formation with significantly higher melting temperatures than X-C or X-U containing RNAs and higher still than A-U or G-U containing RNA references. Furthermore, nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallographic structure analysis confirmed the tridendate Watson-Crick pair geometry of K-X within an RNA double helix. Our findings suggest that K-X and 2imC-X pairs could be used in RNA decoding processes, thereby expanding the RNA genetic alphabet. However, their potential for use in biochemical and cellular applications remains to be seen.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 6,
  "authors": [
    {
      "name": "Stefan Mair"
    },
    {
      "name": "Anna Rázková"
    },
    {
      "name": "Karl Brillet"
    },
    {
      "name": "Catherina Gasser"
    },
    {
      "name": "Eric Ennifar"
    },
    {
      "name": "Ronald Micura"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/c1bxfwfbgbjfr.bib",
  "cited_by": 2,
  "doi": "10.1002/chem.202501860",
  "fulltext_url": null,
  "id": "c1bxfwfbgbjfr",
  "issns": [
    "0947-6539",
    "1521-3765"
  ],
  "landing_url": "https://hal.science/hal-05772521v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.sdv"
    ],
    [
      "hal",
      "1.sdv.bbm"
    ],
    [
      "hal",
      "2.sdv.bbm.bc"
    ],
    [
      "hal",
      "2.sdv.bbm.bp"
    ],
    [
      "hal",
      "2.sdv.bbm.bs"
    ],
    [
      "openalex",
      "1312|DNA and Nucleic Acid Chemistry"
    ]
  ],
  "openalex": "W4411434015",
  "pdf_url": "https://hal.science/hal-05772521/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": "Wiley-VCH Verlag",
  "ris": "https://research.draconitic.com/paper/c1bxfwfbgbjfr.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:44Z",
      "native_id": "hal-05772521",
      "source": "hal",
      "url": "https://hal.science/hal-05772521v1"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "hal:2.sdv.bbm.bp",
      "subfield": "biophysics"
    },
    {
      "field": "biochemistry",
      "origin": "hal:2.sdv.bbm.bs",
      "subfield": "structural-biology"
    },
    {
      "field": "biology",
      "origin": "hal:0.sdv",
      "subfield": "general"
    }
  ],
  "title": "Tailored Watson–Crick Pairing Partners for Xanthosine in RNA",
  "title_text": "Tailored Watson–Crick Pairing Partners for Xanthosine in RNA",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:44Z",
  "url": "https://research.draconitic.com/paper/c1bxfwfbgbjfr",
  "venue": "Chemistry - A European Journal",
  "versions": []
}