7v99
From Proteopedia
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| - | ==== | + | ==catalytic core of human telomerase holoenzyme== |
| - | <StructureSection load='7v99' size='340' side='right'caption='[[7v99]]' scene=''> | + | <StructureSection load='7v99' size='340' side='right'caption='[[7v99]], [[Resolution|resolution]] 3.54Å' scene=''> |
== Structural highlights == | == Structural highlights == | ||
| - | <table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id= OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol= FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[7v99]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7V99 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7V99 FirstGlance]. <br> |
| - | </td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7v99 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7v99 OCA], [https://pdbe.org/7v99 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7v99 RCSB], [https://www.ebi.ac.uk/pdbsum/7v99 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7v99 ProSAT]</span></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.54Å</td></tr> |
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7v99 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7v99 OCA], [https://pdbe.org/7v99 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7v99 RCSB], [https://www.ebi.ac.uk/pdbsum/7v99 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7v99 ProSAT]</span></td></tr> | ||
</table> | </table> | ||
| + | == Disease == | ||
| + | [https://www.uniprot.org/uniprot/TERT_HUMAN TERT_HUMAN] Note=Activation of telomerase has been implicated in cell immortalization and cancer cell pathogenesis. Defects in TERT are associated with susceptibilty to aplastic anemia (AA) [MIM:[https://omim.org/entry/609135 609135]. AA is a rare disease in which the reduction of the circulating blood cells results from damage to the stem cell pool in bone marrow. In most patients, the stem cell lesion is caused by an autoimmune attack. T-lymphocytes, activated by an endogenous or exogenous, and most often unknown antigenic stimulus, secrete cytokines, including IFN-gamma, which would in turn be able to suppress hematopoiesis.<ref>PMID:15885610</ref> <ref>PMID:16627250</ref> <ref>PMID:16990594</ref> <ref>PMID:19760749</ref> Note=Genetic variations in TERT are associated with coronary artery disease (CAD).<ref>PMID:16890917</ref> Defects in TERT are the cause of dyskeratosis congenita autosomal dominant type 2 (DKCA2) [MIM:[https://omim.org/entry/613989 613989]. A rare multisystem disorder caused by defective telomere maintenance. It is characterized by progressive bone marrow failure, and the clinical triad of reticulated skin hyperpigmentation, nail dystrophy, and mucosal leukoplakia. Common but variable features include premature graying, aplastic anemia, low platelets, osteoporosis, pulmonary fibrosis, and liver fibrosis among others. Early mortality is often associated with bone marrow failure, infections, fatal pulmonary complications, or malignancy.<ref>PMID:15885610</ref> <ref>PMID:16247010</ref> Defects in TERT are the cause of pulmonary fibrosis, and/or bone marrow failure, telomere-related, type 1 (PFBMFT1) [MIM:[https://omim.org/entry/614742 614742]. A disease associated with shortened telomeres. Pulmonary fibrosis is the most common manifestation. Other manifestations include aplastic anemia due to bone marrow failure, hepatic fibrosis, and increased cancer risk, particularly myelodysplastic syndrome and acute myeloid leukemia. Phenotype, age at onset, and severity are determined by telomere length. infections, fatal pulmonary complications, or malignancy.<ref>PMID:15814878</ref> <ref>PMID:17460043</ref> <ref>PMID:21436073</ref> <ref>PMID:21483807</ref> <ref>PMID:22512499</ref> Defects in TERT are the cause of dyskeratosis congenita autosomal recessive type 4 (DKCB4) [MIM:[https://omim.org/entry/613989 613989]. A rare multisystem disorder caused by defective telomere maintenance. It is characterized by progressive bone marrow failure, and the clinical triad of reticulated skin hyperpigmentation, nail dystrophy, and mucosal leukoplakia. Common but variable features include premature graying, aplastic anemia, low platelets, osteoporosis, pulmonary fibrosis, and liver fibrosis among others. Early mortality is often associated with bone marrow failure, infections, fatal pulmonary complications, or malignancy. Defects in TERT are a cause of susceptibility to pulmonary fibrosis idiopathic (IPF) [MIM:[https://omim.org/entry/178500 178500]. Pulmonary fibrosis is a lung disease characterized by shortness of breath, radiographically evident diffuse pulmonary infiltrates, and varying degrees of inflammation and fibrosis on biopsy. It results in acute lung injury with subsequent scarring and endstage lung disease. | ||
| + | == Function == | ||
| + | [https://www.uniprot.org/uniprot/TERT_HUMAN TERT_HUMAN] Telomerase is a ribonucleoprotein enzyme essential for the replication of chromosome termini in most eukaryotes. Active in progenitor and cancer cells. Inactive, or very low activity, in normal somatic cells. Catalytic component of the teleromerase holoenzyme complex whose main activity is the elongation of telomeres by acting as a reverse transcriptase that adds simple sequence repeats to chromosome ends by copying a template sequence within the RNA component of the enzyme. Catalyzes the RNA-dependent extension of 3'-chromosomal termini with the 6-nucleotide telomeric repeat unit, 5'-TTAGGG-3'. The catalytic cycle involves primer binding, primer extension and release of product once the template boundary has been reached or nascent product translocation followed by further extension. More active on substrates containing 2 or 3 telomeric repeats. Telomerase activity is regulated by a number of factors including telomerase complex-associated proteins, chaperones and polypeptide modifiers. Modulates Wnt signaling. Plays important roles in aging and antiapoptosis.<ref>PMID:9389643</ref> <ref>PMID:14963003</ref> <ref>PMID:15082768</ref> <ref>PMID:15857955</ref> <ref>PMID:17026956</ref> <ref>PMID:17548608</ref> <ref>PMID:17296728</ref> <ref>PMID:17264120</ref> <ref>PMID:19188162</ref> <ref>PMID:19567472</ref> <ref>PMID:19571879</ref> <ref>PMID:19777057</ref> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Telomerase, a multi-subunit ribonucleoprotein complex, is a unique reverse transcriptase that catalyzes the processive addition of a repeat sequence to extend the telomere end using a short fragment of its own RNA component as the template. Despite recent structural characterizations of human and Tetrahymena telomerase, it is still a mystery how telomerase repeatedly uses its RNA template to synthesize telomeric DNA. Here, we report the cryo-EM structure of human telomerase holoenzyme bound with telomeric DNA at resolutions of 3.5 A and 3.9 A for the catalytic core and biogenesis module, respectively. The structure reveals that a leucine residue Leu980 in telomerase reverse transcriptase (TERT) catalytic subunit functions as a zipper head to limit the length of the short primer-template duplex in the active center. Moreover, our structural and computational analyses suggest that TERT and telomerase RNA (hTR) are organized to harbor a preformed active site that can accommodate short primer-template duplex substrates for catalysis. Furthermore, our findings unveil a double-fingers architecture in TERT that ensures nucleotide addition processivity of human telomerase. We propose that the zipper head Leu980 is a structural determinant for the sequence-based pausing signal of DNA synthesis that coincides with the RNA element-based physical template boundary. Functional analyses unveil that the non-glycine zipper head plays an essential role in both telomerase repeat addition processivity and telomere length homeostasis. In addition, we also demonstrate that this zipper head mechanism is conserved in all eukaryotic telomerases. Together, our study provides an integrated model for telomerase-mediated telomere synthesis. | ||
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| + | Zipper head mechanism of telomere synthesis by human telomerase.,Wan F, Ding Y, Zhang Y, Wu Z, Li S, Yang L, Yan X, Lan P, Li G, Wu J, Lei M Cell Res. 2021 Dec;31(12):1275-1290. doi: 10.1038/s41422-021-00586-7. Epub 2021 , Nov 15. PMID:34782750<ref>PMID:34782750</ref> | ||
| + | |||
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
| + | </div> | ||
| + | <div class="pdbe-citations 7v99" style="background-color:#fffaf0;"></div> | ||
| + | |||
| + | ==See Also== | ||
| + | *[[Telomerase 3D structures|Telomerase 3D structures]] | ||
| + | == References == | ||
| + | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
| + | [[Category: Homo sapiens]] | ||
[[Category: Large Structures]] | [[Category: Large Structures]] | ||
| - | [[Category: Z | + | [[Category: Ding Y]] |
| + | [[Category: Lei M]] | ||
| + | [[Category: Wan F]] | ||
| + | [[Category: Wu J]] | ||
| + | [[Category: Wu Z]] | ||
| + | [[Category: Yang L]] | ||
Current revision
catalytic core of human telomerase holoenzyme
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Categories: Homo sapiens | Large Structures | Ding Y | Lei M | Wan F | Wu J | Wu Z | Yang L
