5e8b
From Proteopedia
Crystal structure of the S. cerevisiae Rtf1 histone modification domain mutant R126A
Structural highlights
FunctionRTF1_YEAST The PAF1 complex is a multifunctional complex. Involved in transcription initiation via genetic interactions with TATA-binding proteins. Involved in elongation. It regulates 3'-end formation of snR47 by modulating the recruitment or stable association of NRD1 and NAB3 with RNA polymerase II. Also has a role in transcription-coupled histone modification. Required for activation of RAD6 ubiquitin conjugate and the BRE1 ubiquitin ligase which ubiquitinate 'Lys-126' histone H2B. Activates the SET1 histone methyltransferase complex for methylation of 'Lys-4' of histone H3 and for methylation of 'Lys-73' of histone H3 by DOT1 and 'Lys-36' of histone H3 by SET2. Important for TATA site selection by TBP. Directly or indirectly regulates the DNA-binding properties of SPT15, the TATA box-binding protein, and the relative activities of different TATA elements.[1] [2] Publication Abstract from PubMedThe five-subunit yeast Paf1 complex (Paf1C) regulates all stages of transcription and is critical for the monoubiquitylation of histone H2B (H2Bub), a modification that broadly influences chromatin structure and eukaryotic transcription. Here, we show that the histone modification domain (HMD) of Paf1C subunit Rtf1 directly interacts with the ubiquitin conjugase Rad6 and stimulates H2Bub independently of transcription. We present the crystal structure of the Rtf1 HMD and use site-specific, in vivo crosslinking to identify a conserved Rad6 interaction surface. Utilizing ChIP-exo analysis, we define the localization patterns of the H2Bub machinery at high resolution and demonstrate the importance of Paf1C in targeting the Rtf1 HMD, and thereby H2Bub, to its appropriate genomic locations. Finally, we observe HMD-dependent stimulation of H2Bub in a transcription-free, reconstituted in vitro system. Taken together, our results argue for an active role for Paf1C in promoting H2Bub and ensuring its proper localization in vivo. The Histone Modification Domain of Paf1 Complex Subunit Rtf1 Directly Stimulates H2B Ubiquitylation through an Interaction with Rad6.,Van Oss SB, Shirra MK, Bataille AR, Wier AD, Yen K, Vinayachandran V, Byeon IL, Cucinotta CE, Heroux A, Jeon J, Kim J, VanDemark AP, Pugh BF, Arndt KM Mol Cell. 2016 Nov 17;64(4):815-825. doi: 10.1016/j.molcel.2016.10.008. Epub 2016, Nov 10. PMID:27840029[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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