The PRC2 (Polycomb repressive complex 2) complex is a multi-component histone H3K27 methyltransferase, best known for silencing Hox genes during embryonic development. The Polycomb-like proteins PHF1, MTF2 and PHF19 are critical components of PRC2 by stimulating its catalytic activity in embryonic stem (ES) cells. The Tudor domains of PHF1/19 have been previously shown to be readers of H3K36me3 in vitro. However, some other studies suggest that PHF1 and PHF19 co-localize with the H3K27me3 mark, but not H3K36me3 in cells. Here, we provide further evidence that PHF1 co-localizes with H3t in testis, and its Tudor domain preferentially binds to H3tK27me3 over canonical H3K27me3 in vitro. Our complex structures of the Tudor domains of PHF1 and PHF19 with H3tK27me3 shed light on the molecular basis for preferential recognition of H3tK27me3 by PHF1 and PHF19 over canonical H3K27me3, implicating that H3tK27me3 might be a physiological ligand of PHF1/19.
Diffraction data have been deposited in PDB under the accession codes 6WAT, 6WAU, 6WAV
Complex structure of PHF1Protein Data Bank, 6WAT.
Complex structure of PHF19Protein Data Bank, 6WAU.
Crystal structure of PHF1 in complex with H3K36me3 substitutionProtein Data Bank, 6WAV.
- Cheng Dong
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Xiaobing Shi, Van Andel Institute, United States
© 2020, Dong et al.
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