Figure 7. Summary of residues on EZH2 of ctPRC2 and hsPRC2 that are important for binding G-quadruplex RNA.

(A) Crystal structure of a telomeric RNA quadruplex (PDB: 3IBK, sequence: UAGGGUUAGGGU) allows comparison of its size with that of PRC2 structures. Blue spheres in the center are potassium ions. (B and C) Identified key residues for RNA binding are shown in red. Subunits of PRC2 are colored differently. (C) Locations of the key residues for RNA binding are annotated along the polypeptide chain. Key residues in ctPRC2 are listed above the chain, while those in hsPRC2 are below the chain. Individual domains are color-coded as in Figure 2A. K656 mutation increases catalytic activity and is therefore omitted from this annotation map.