Structure of Tetrahymena telomerase-bound CST with polymerase α-primase.
Structure of Tetrahymena telomerase-bound CST with polymerase α-primase.
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DOI：
10.1038/s41586-022-04931-7
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发表时间：
2022-08
期刊：
影响因子：
64.8
通讯作者：
中科院分区：
文献类型：
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端粒是线性染色体的物理末端，由短重复序列（例如，四膜虫的TTGGGG为g链）的双链DNA和g链的单链3 '悬垂组成，在人类中，由一组六种称为庇护蛋白的蛋白质组成。其中，TPP1和POT1与3 ' -悬垂相关，POT1结合g链，TPP1（与TIN2复合物）通过与端粒酶逆转录酶（TERT）相互作用募集端粒酶。端粒DNA末端由端粒酶（对于g链）和随后的DNA聚合酶α-引物酶（PolαPrim）（对于c链）进行复制和维持。PolαPrim活性可通过CTC1-STN1-TEN1 （CST）激活，但PolαPrim和CST在端粒末端募集的结构基础尚不清楚。在这里，我们报告了端粒酶全酶背景下四膜虫CST的低温电镜结构，无论是在没有和存在PolαPrim，还是单独存在PolαPrim的情况下。四膜虫Ctc1结合端粒酶亚基p50，一个TPP1同源物，在一个柔性的Ctc1结合基序上，由冷冻电镜和核磁共振光谱共同揭示。PolαPrim聚合酶亚基POLA1结合Ctc1和Stn1，其与Ctc1的界面形成了g链DNA进入POLA1活性位点的入口。同时，我们获得了端粒DNA合成所需的四个关键参与者的快照-端粒酶核心核糖核蛋白（RNP）， p50/TPP1， CST和PolαPrim -这为CST和PolαPrim的募集以及g链和c链合成之间的切换提供了前所未有的见解。
Telomeres are the physical ends of linear chromosomes, composed of short repeating sequences (e.g. TTGGGG in Tetrahymena for the G-strand) of double-stranded DNA with a single-strand 3’-overhang of the G-strand and, in humans, a group of six proteins called shelterin. Among these, TPP1 and POT1 associate with the 3’-overhang, with POT1 binding the G-strand and TPP1 (in complex with TIN2) recruiting telomerase via interaction with telomerase reverse transcriptase (TERT). The telomere DNA ends are replicated and maintained by telomerase, for the G-strand, and subsequently DNA Polymerase α-Primase (PolαPrim), for the C-strand. PolαPrim activity is stimulated by CTC1–STN1–TEN1 (CST), but the structural basis of PolαPrim and CST recruitment to telomere ends remains unknown. Here we report cryo-EM structures of Tetrahymena CST in the context of telomerase holoenzyme, both in the absence and presence of PolαPrim, and of PolαPrim alone. Tetrahymena Ctc1 binds telomerase subunit p50, a TPP1 ortholog, on a flexible Ctc1 binding motif unveiled jointly by cryo-EM and NMR spectroscopy. PolαPrim polymerase subunit POLA1 binds Ctc1 and Stn1, and its interface with Ctc1 forms an entry port for G-strand DNA to the POLA1 active site. Together, we obtained a snapshot of four key players required for telomeric DNA synthesis in a single active complex—telomerase core ribonucleoprotein (RNP), p50/TPP1, CST and PolαPrim—that provides unprecedented insights into CST and PolαPrim recruitment and handoff between G-strand and C-strand synthesis.
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影响因子：
14.9
作者：
Beseiso D;Chen EV;McCarthy SE;Martin KN;Gallagher EP;Miao J;Yatsunyk LA
通讯作者：
Yatsunyk LA
影响因子：
64.8
作者：
Chen, Liuh-Yow;Redon, Sophie;Lingner, Joachim
通讯作者：
Lingner, Joachim
影响因子：
64.8
作者：
Ghanim GE;Fountain AJ;van Roon AM;Rangan R;Das R;Collins K;Nguyen THD
通讯作者：
Nguyen THD
对人类癌症中 POT1-TPP1 相互作用和 POT1 C 末端突变的结构见解。
影响因子：
16.6
作者：
Chen C;Gu P;Wu J;Chen X;Niu S;Sun H;Wu L;Li N;Peng J;Shi S;Fan C;Huang M;Wong CC;Gong Q;Kumar-Sinha C;Zhang R;Pusztai L;Rai R;Chang S;Lei M
通讯作者：
Lei M
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH