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-Structure paper
Title | Structures of +1 nucleosome-bound PIC-Mediator complex. |
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Journal, issue, pages | Science, Vol. 378, Issue 6615, Page 62-68, Year 2022 |
Publish date | Oct 7, 2022 |
Authors | Xizi Chen / Xinxin Wang / Weida Liu / Yulei Ren / Xuechun Qu / Jiabei Li / Xiaotong Yin / Yanhui Xu / |
PubMed Abstract | RNA polymerase II-mediated eukaryotic transcription starts with the assembly of the preinitiation complex (PIC) on core promoters. The +1 nucleosome is well positioned about 40 base pairs downstream ...RNA polymerase II-mediated eukaryotic transcription starts with the assembly of the preinitiation complex (PIC) on core promoters. The +1 nucleosome is well positioned about 40 base pairs downstream of the transcription start site (TSS) and is commonly known as a barrier of transcription. The +1 nucleosome-bound PIC-Mediator structures show that PIC-Mediator prefers binding to T40N nucleosome located 40 base pairs downstream of TSS and contacts T50N but not the T70N nucleosome. The nucleosome facilitates the organization of PIC-Mediator on the promoter by binding TFIIH subunit p52 and Mediator subunits MED19 and MED26 and may contribute to transcription initiation. PIC-Mediator exhibits multiple nucleosome-binding patterns, supporting a structural role of the +1 nucleosome in the coordination of PIC-Mediator assembly. Our study reveals the molecular mechanism of PIC-Mediator organization on chromatin and underscores the significance of the +1 nucleosome in regulating transcription initiation. |
External links | Science / PubMed:36201575 |
Methods | EM (single particle) |
Resolution | 4.16 - 15.18 Å |
Structure data | EMDB-33867: PIC-Mediator (MED26-mut) in complex with +1 nucleosome (T40N) EMDB-33885: PIC-Mediator (MED19-mut) in complex with +1 nucleosome (T40N) EMDB-33886: PIC-Mediator (MED19-MED26 double mutant) in complex with +1 nucleosome (T40N) EMDB-34215: PIC-Mediator in complex with +1 nucleosome (T50N) EMDB-34255: PIC-Mediator (p52-mut) in complex with +1 nucleosome (T40N) EMDB-34256: PIC-Mediator in complex with +1 H2A-containing nucleosome (T40N) EMDB-34257: PIC-Mediator in complex with +1 nucleosome (T70N) EMDB-34359, PDB-8gxq: EMDB-34360, PDB-8gxs: |
Chemicals | ChemComp-ZN: ChemComp-SF4: ChemComp-MG: |
Source |
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Keywords | TRANSCRIPTION / PIC / Mediator / transcription initiation / +1 nucleosome |