6QAJ
Structure of the tripartite motif of KAP1/TRIM28
Summary for 6QAJ
| Entry DOI | 10.2210/pdb6qaj/pdb |
| Descriptor | Endolysin,Transcription intermediary factor 1-beta, ZINC ION (2 entities in total) |
| Functional Keywords | transcriptional repressor; epigenetic silencing; histone h3 lysine 9 methylation (h3k9me3); endogenous retrovirus; retrotransposon; transposable element; tripartite motif (trim); sumo; ubiquitin; e3 ligase, nuclear protein |
| Biological source | Enterobacteria phage T4 (Bacteriophage T4) More |
| Total number of polymer chains | 2 |
| Total formula weight | 123466.98 |
| Authors | Stoll, G.A.,Oda, S.,Yu, M.,Modis, Y. (deposition date: 2018-12-19, release date: 2019-07-24, Last modification date: 2024-10-16) |
| Primary citation | Stoll, G.A.,Oda, S.I.,Chong, Z.S.,Yu, M.,McLaughlin, S.H.,Modis, Y. Structure of KAP1 tripartite motif identifies molecular interfaces required for retroelement silencing. Proc.Natl.Acad.Sci.USA, 116:15042-15051, 2019 Cited by PubMed Abstract: Transcription of transposable elements is tightly regulated to prevent genome damage. KRAB domain-containing zinc finger proteins (KRAB-ZFPs) and KRAB-associated protein 1 (KAP1/TRIM28) play a key role in regulating retrotransposons. KRAB-ZFPs recognize specific retrotransposon sequences and recruit KAP1, inducing the assembly of an epigenetic silencing complex, with chromatin remodeling activities that repress transcription of the targeted retrotransposon and adjacent genes. Our biophysical and structural data show that the tripartite motif (TRIM) of KAP1 forms antiparallel dimers, which further assemble into tetramers and higher-order oligomers in a concentration-dependent manner. Structure-based mutations in the B-box 1 domain prevent higher-order oligomerization without significant loss of retrotransposon silencing activity, indicating that, in contrast to other TRIM-family proteins, self-assembly is not essential for KAP1 function. The crystal structure of the KAP1 TRIM dimer identifies the KRAB domain binding site in the coiled-coil domain near the dyad. Mutations at this site abolished KRAB binding and transcriptional silencing activity of KAP1. This work identifies the interaction interfaces in the KAP1 TRIM responsible for self-association and KRAB binding and establishes their role in retrotransposon silencing. PubMed: 31289231DOI: 10.1073/pnas.1901318116 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.901 Å) |
Structure validation
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