E3 ubiquitin-protein ligase TRIM21-mediated lysine capture by UBE2E1 reveals substrate-targeting mode of a ubiquitin-conjugating E2Show others and affiliations
2019 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, JOURNAL OF BIOLOGICAL CHEMISTRY, Vol. 294, no 30, p. 11404-11419Article in journal (Refereed) Published
Abstract [en]
The E3 ubiquitin-protein ligase TRIM21, of the RING-containing tripartite motif (TRIM) protein family, is a major autoantigen in autoimmune diseases and a modulator of innate immune signaling. Together with ubiquitin-conjugating enzyme E2 E1 (UBE2E1), TRIM21 acts both as an E3 ligase and as a substrate in autoubiquitination. We here report a 2.82-angstrom crystal structure of the human TRIM21 RING domain in complex with the human E2-conjugating UBE2E1 enzyme, in which a ubiquitin-targeted TRIM21 substrate lysine was captured in the UBE2E1 active site. The structure revealed that the direction of lysine entry is similar to that described for human proliferating cell nuclear antigen (PCNA), a small ubiquitin-like modifier (SUMO)-targeted substrate, and thus differs from the canonical SUMO-targeted substrate entry. In agreement, we found that critical UBE2E1 residues involved in the capture of the TRIM21 substrate lysine are conserved in ubiquitin-conjugating E2s, whereas residues critical for SUMOylation are not conserved. We noted that coordination of the acceptor lysine leads to remodeling of amino acid side-chain interactions between the UBE2E1 active site and the E2-E3 direct interface, including the so-called linchpin residue conserved in RING E3s and required for ubiquitination. The findings of our work support the notion that substrate lysine activation of an E2-E3-connecting allosteric path may trigger catalytic activity and contribute to the understanding of specific lysine targeting by ubiquitin-conjugating E2s.
Place, publisher, year, edition, pages
American Society for Biochemistry and Molecular Biology, 2019. Vol. 294, no 30, p. 11404-11419
Keywords [en]
ubiquitin-conjugating enzyme (E2 enzyme); substrate specificity; E3 ubiquitin ligase; ubiquitin; allosteric regulation
National Category
Structural Biology
Identifiers
URN: urn:nbn:se:liu:diva-159721DOI: 10.1074/jbc.RA119.008485ISI: 000478717600006PubMedID: 31160341Scopus ID: 2-s2.0-85070057958OAI: oai:DiVA.org:liu-159721DiVA, id: diva2:1343873
Note
Funding Agencies|Swedish Research Council; Swedish Rheumatism Association; Swedish Heart-Lung Foundation; Stockholm County Council; King Gustaf the Vth 80-year foundation; Karolinska Institutet; Swedish Foundation for International Cooperation in Research and Higher Education; Swedish Child Cancer Foundation; Swedish Cancer Foundation; Carl Trygger Foundation; Linkoping University
2019-08-192019-08-192019-08-26Bibliographically approved