5vey
From Proteopedia
Solution NMR structure of histone H2A-H2B mono-ubiquitylated at H2A Lys15 in complex with RNF169 (653-708)
Structural highlights
FunctionH2B1J_HUMAN Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling.[1] [2] [3] Has broad antibacterial activity. May contribute to the formation of the functional antimicrobial barrier of the colonic epithelium, and to the bactericidal activity of amniotic fluid.[4] [5] [6] H2A1B_HUMAN Publication Abstract from PubMedThe protein 53BP1 plays a central regulatory role in DNA double-strand break repair. 53BP1 relocates to chromatin by recognizing RNF168-mediated mono-ubiquitylation of histone H2A Lys15 in the nucleosome core particle dimethylated at histone H4 Lys20 (NCP-ubme). 53BP1 relocation is terminated by ubiquitin ligases RNF169 and RAD18 via unknown mechanisms. Using nuclear magnetic resonance (NMR) spectroscopy and biochemistry, we show that RNF169 bridges ubiquitin and histone surfaces, stabilizing a pre-existing ubiquitin orientation in NCP-ubme to form a high-affinity complex. This conformational selection mechanism contrasts with the low-affinity binding mode of 53BP1, and it ensures 53BP1 displacement by RNF169 from NCP-ubme. We also show that RAD18 binds tightly to NCP-ubme through a ubiquitin-binding domain that contacts ubiquitin and nucleosome surfaces accessed by 53BP1. Our work uncovers diverse ubiquitin recognition mechanisms in the nucleosome, explaining how RNF168, RNF169, and RAD18 regulate 53BP1 chromatin recruitment and how specificity can be achieved in the recognition of a ubiquitin-modified substrate. Mechanisms of Ubiquitin-Nucleosome Recognition and Regulation of 53BP1 Chromatin Recruitment by RNF168/169 and RAD18.,Hu Q, Botuyan MV, Cui G, Zhao D, Mer G Mol Cell. 2017 May 18;66(4):473-487.e9. doi: 10.1016/j.molcel.2017.04.009. Epub, 2017 May 11. PMID:28506460[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||
Categories: Homo sapiens | Large Structures | Botuyan MV | Cui G | Hu Q | Mer G
