Unleashing the Power of ASH1L Methyltransferase

Trithorax histone methyltransferase Ash1/ASH1L is tightly regulated because it activates developmental gene transcription and counteracts Polycomb silencing. In this issue of Structure, Lee et al. (2019) Lee Y. Yoon E. Cho S. Schm？hling S. Müller J. Song J.-J. Structural basis of MRG15-mediated activation of the ASH1L histone methyltransferase by releasing an autoinhibitory loop. Structure. 2019; 27 ( this issue) : 846-852 Google Scholar and Hou et al. (2019) Hou P. Huang C. Liu C.-P. Yang N. Yu T. Yin Y. Zhu B. Xu R.-M. Structural insights into stimulation of Ash1L’s H3K36 methyltransferase activity through Mrg15 binding. Structure. 2019; 27 ( this issue) : 837-845 Google Scholar report the crystal structure of ASH1L bound to its activator MRG15 and suggest a mechanism that releases ASH1L auto-inhibition