6qxz
From Proteopedia
Solution structure of the ASHH2 CW domain with the N-terminal histone H3 tail mimicking peptide monomethylated on lysine 4
Structural highlights
Function[ASHH2_ARATH] Histone methyltransferase involved in di and tri-methylation of 'Lys-36' of histone H3 (H3K36me2 and H3K36me3). Binds to H3 already mono- or di-methylated on 'Lys-4'(H3K4me1 or H3K4me2), but not to H3K4me3. H3K4me and H3K36me represent specific tags for epigenetic transcriptional activation. Regulates positively FLC transcription to prevent early flowering transition. Required for flowering transition in response to vernalization and for the maintenance of FLC expression in late embryos, but dispensable for the initial reactivation in early embryos during reprogramming. Seems also to modulate several traits including floral organ size, root size and dormancy. Promotes apical dominance (PubMed:16299497, PubMed:10518493, PubMed:16258034, PubMed:18070919, PubMed:19915673, PubMed:20711170). Directly involved in the tri-methylation of 'Lys-36' of histone H3 (H3K36me3) at LAZ5 chromatin to maintain a transcriptionally active state of LAZ5, a TIR-NB-LRR protein involved in innate immunity (PubMed:20949080).[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedThe 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 (Kd values reported in the range of 1 microm 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 affinity 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. (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.,Dobrovolska O, Bril'kov M, Odegard-Fougner O, Aasland R, Halskau O Biomol NMR Assign. 2018 Apr;12(1):215-220. doi: 10.1007/s12104-018-9811-x. Epub, 2018 Feb 16. PMID:29453713[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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