Vol.:(0123456789) 1 3 Biomolecular NMR Assignments https://doi.org/10.1007/s12104-018-9811-x ARTICLE 1 H, 13 C, and  15 N resonance assignments of CW domain of the N- methyltransferase ASHH2 free and bound to the mono-, di- and tri- methylated histone H3 tail peptides Olena Dobrovolska 1  · Maxim Bril’kov 1  · Øyvind Ødegård‑Fougner 2  · Rein Aasland 3  · Øyvind Halskau 1 Received: 1 December 2017 / Accepted: 8 February 2018 © Springer Science+Business Media B.V., part of Springer Nature 2018 Abstract The ASHH2 CW domain is responsible for recognizing the methylation state at lysine 4 of histone 3 N-terminal tails and implicated in the recruitment of the ASHH2 methyltransferase enzyme correctly to the histones. The ASHH2 CW domain binds H3 lysine motifs that can be either mono-, di-, or tri-methylated [ARTK(meX)QTAR, where X denotes the number of methylations], but binds strongest to monomethylated instances (K d values reported in the range of 1 µm to 500 nM). Hoppmann et al. published the uncomplexed NMR structure of an ASHH2 CW domain in 2011. Here we document the assignment of a shortened ASHH2 CW construct, CW42, with similar binding afnity and better expression yields than the one used to solve the uncomplexed structure. We also perform 1 H– 15 N HSQC-monitored titrations that document at which protein–peptide ratios the complex is saturated. Backbone resonance assignments are presented for this shortened ASHH2 CW domain alone and bound to an H3 histone tail mimicking peptide monomethylated on lysine 4 (ARTK(me1)QTAR). Likewise, the assignment was also performed for the protein in complex with the dimethylated (ARTK(me2)QTAR) and trimethylated (ARTK(me3)QTAR) peptide. Overall, these two latter situations displayed a similar perturbation of shifts as the mono-methylated instance. In the case of the monomethylated histone tail mimic, side-chain assignment of CW42 in this complex was performed and reported in addition to backbone assignment, in preparation of a future solution structure determination and dynamics characterization of the CW42–ARTK(me1)QTAR complex. Keywords CW · Methylation · Histone-tail modifcation · Assignment Abbreviations H3 Histone 3 H3K4me1 ARTK(me1)QTAR H3K4me2 ARTK(me2)QTAR H3K4me3 ARTK(me3)QTAR PTM Post-translational modifcation Biological context Histone methylations are post-translational modifcations (PTMs) found on the N-terminal tails of the histones. Together with acetylation, these PTMs constitute an impor- tant part of epigenetic control mechanisms by making the DNA wound around the histone octamers either more acces- sible or less accessible to transcription (Gasser et al. 1998; Grewal and Jia 2007). Both the PTM type, which histone is modifed, and the position on the particular histone tail matter as well as combinatorial efects. For instance, high levels of methylation at lysine 9 on the N-terminal tail of histone 3 (H3) along with low levels of acetylation are asso- ciated with heterochromatin, a tightly packed DNA confgu- ration that is inaccessible to transcription (Mellor 2006). In contrast, methylation at lysine 36 on H3 is associated with transcribing genes (Zhao et al. 2005; Morris et al. 2005). Acetyltransferase and methyltransferase activities are medi- ated through a diverse group of multidomain proteins. Typi- cally, interaction domains associated with correct targeting, Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12104-018-9811-x) contains supplementary material, which is available to authorized users. * Olena Dobrovolska olena.dobrovolska@uib.no 1 Department of Biological Sciences, University of Bergen, Thormøhlensgate, 55, 5008 Bergen, Norway 2 Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117 Heidelberg, Germany 3 Department of Biosciences, University of Oslo, Kristine Bonnevies Hus, Blindernveien 31, 0371 Oslo, Norway