We determined the three-dimensional structure of the PHD finger of the rice Siz/PIAS-type SUMO ligase, OsSiz1, by NMR spectroscopy and investigated binding ability for a variety of methylated histone H3 tails, showing that OsSiz1-PHD primarily recognizes dimethylated Arg2 of the histone H3 and that methylations at Arg2 and Lys4 reveal synergy effect on binding to OsSiz1-PHD. The K4 cage of OsSiz1-PHD for trimethylated Lys4 of H3K4me3 was similar to that of the BPTF-PHD finger, while the R2 pocket for Arg2 was different. It is intriguing that the PHD module of Siz/PIAS plays an important role, with collaboration with the DNA binding domain SAP, in gene regulation through SUMOylation of a variety of effectors associated with the methylated arginine-riched chromatin domains. © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Shindo, H., Suzuki, R., Tsuchiya, W., Taichi, M., Nishiuchi, Y., & Yamazaki, T. (2012). PHD finger of the SUMO ligase Siz/PIAS family in rice reveals specific binding for methylated histone H3 at lysine 4 and arginine 2. FEBS Letters, 586(13), 1783–1789. https://doi.org/10.1016/j.febslet.2012.04.063