| Structural highlights
5un7 is a 2 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , |
| Gene: | POT1 (HUMAN), ACD, PIP1, PTOP, TINT1, TPP1 (HUMAN) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[POTE1_HUMAN] Component of the telomerase ribonucleoprotein (RNP) complex that is essential for the replication of chromosome termini. Is a component of the double-stranded telomeric DNA-binding TRF1 complex which is involved in the regulation of telomere length by cis-inhibition of telomerase. Also acts as a single-stranded telomeric DNA-binding protein and thus may act as a downstream effector of the TRF1 complex and may transduce information about telomere maintenance and/or length to the telomere terminus. Component of the shelterin complex (telosome) that is involved in the regulation of telomere length and protection. Shelterin associates with arrays of double-stranded TTAGGG repeats added by telomerase and protects chromosome ends; without its protective activity, telomeres are no longer hidden from the DNA damage surveillance and chromosome ends are inappropriately processed by DNA repair pathways. Binds to two or more telomeric single-stranded 5'-TTAGGG-3' repeats (G-strand) and with high specificity to a minimal telomeric single-stranded 5'-TAGGGTTAG-3' sequence. Binds telomeric single-stranded sequences internally or at proximity of a 3'-end. Its activity is TERT dependent but it does not increase TERT activity by itself. In contrast, the ACD-POT1 heterodimer enhances telomere elongation by increasing telomerase processivity.[1] [2] [3] [4] [5] [ACD_HUMAN] Component of the shelterin complex (telosome) that is involved in the regulation of telomere length and protection. Shelterin associates with arrays of double-stranded TTAGGG repeats added by telomerase and protects chromosome ends; without its protective activity, telomeres are no longer hidden from the DNA damage surveillance and chromosome ends are inappropriately processed by DNA repair pathways. Promotes binding of POT1 to single-stranded telomeric DNA. Modulates the inhibitory effects of POT1 on telomere elongation. The ACD-POT1 heterodimer enhances telomere elongation by increasing telomerase processivity. Plays a role in shelterin complex assembly. May play a role in organogenesis.[6] [7] [8] [9] [10]
Publication Abstract from PubMed
POT1 and TPP1 are part of the shelterin complex and are essential for telomere length regulation and maintenance. Naturally occurring mutations of the telomeric POT1-TPP1 complex are implicated in familial glioma, melanoma and chronic lymphocytic leukaemia. Here we report the atomic structure of the interacting portion of the human telomeric POT1-TPP1 complex and suggest how several of these mutations contribute to malignant cancer. The POT1 C-terminus (POT1C) forms a bilobal structure consisting of an OB-fold and a holiday junction resolvase domain. TPP1 consists of several loops and helices involved in extensive interactions with POT1C. Biochemical data shows that several of the cancer-associated mutations, partially disrupt the POT1-TPP1 complex, which affects its ability to bind telomeric DNA efficiently. A defective POT1-TPP1 complex leads to longer and fragile telomeres, which in turn promotes genomic instability and cancer.
Structural and functional analysis of the human POT1-TPP1 telomeric complex.,Rice C, Shastrula PK, Kossenkov AV, Hills R, Baird DM, Showe LC, Doukov T, Janicki S, Skordalakes E Nat Commun. 2017 Apr 10;8:14928. doi: 10.1038/ncomms14928. PMID:28393830[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Colgin LM, Baran K, Baumann P, Cech TR, Reddel RR. Human POT1 facilitates telomere elongation by telomerase. Curr Biol. 2003 May 27;13(11):942-6. PMID:12781132
- ↑ Loayza D, De Lange T. POT1 as a terminal transducer of TRF1 telomere length control. Nature. 2003 Jun 26;423(6943):1013-8. Epub 2003 May 25. PMID:12768206 doi:10.1038/nature01688
- ↑ de Lange T. Shelterin: the protein complex that shapes and safeguards human telomeres. Genes Dev. 2005 Sep 15;19(18):2100-10. PMID:16166375 doi:10.1101/gad.1346005
- ↑ Wang F, Podell ER, Zaug AJ, Yang Y, Baciu P, Cech TR, Lei M. The POT1-TPP1 telomere complex is a telomerase processivity factor. Nature. 2007 Feb 1;445(7127):506-10. Epub 2007 Jan 21. PMID:17237768 doi:nature05454
- ↑ Zaug AJ, Podell ER, Nandakumar J, Cech TR. Functional interaction between telomere protein TPP1 and telomerase. Genes Dev. 2010 Mar 15;24(6):613-22. doi: 10.1101/gad.1881810. PMID:20231318 doi:10.1101/gad.1881810
- ↑ Liu D, Safari A, O'Connor MS, Chan DW, Laegeler A, Qin J, Songyang Z. PTOP interacts with POT1 and regulates its localization to telomeres. Nat Cell Biol. 2004 Jul;6(7):673-80. Epub 2004 Jun 6. PMID:15181449 doi:http://dx.doi.org/10.1038/ncb1142
- ↑ de Lange T. Shelterin: the protein complex that shapes and safeguards human telomeres. Genes Dev. 2005 Sep 15;19(18):2100-10. PMID:16166375 doi:10.1101/gad.1346005
- ↑ O'Connor MS, Safari A, Xin H, Liu D, Songyang Z. A critical role for TPP1 and TIN2 interaction in high-order telomeric complex assembly. Proc Natl Acad Sci U S A. 2006 Aug 8;103(32):11874-9. Epub 2006 Jul 31. PMID:16880378 doi:0605303103
- ↑ Zaug AJ, Podell ER, Nandakumar J, Cech TR. Functional interaction between telomere protein TPP1 and telomerase. Genes Dev. 2010 Mar 15;24(6):613-22. doi: 10.1101/gad.1881810. PMID:20231318 doi:10.1101/gad.1881810
- ↑ Wang F, Podell ER, Zaug AJ, Yang Y, Baciu P, Cech TR, Lei M. The POT1-TPP1 telomere complex is a telomerase processivity factor. Nature. 2007 Feb 1;445(7127):506-10. Epub 2007 Jan 21. PMID:17237768 doi:nature05454
- ↑ Rice C, Shastrula PK, Kossenkov AV, Hills R, Baird DM, Showe LC, Doukov T, Janicki S, Skordalakes E. Structural and functional analysis of the human POT1-TPP1 telomeric complex. Nat Commun. 2017 Apr 10;8:14928. doi: 10.1038/ncomms14928. PMID:28393830 doi:http://dx.doi.org/10.1038/ncomms14928
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