3l82
From Proteopedia
X-ray Crystal structure of TRF1 and Fbx4 complex
Structural highlights
Function[TERF1_HUMAN] Binds the telomeric double-stranded TTAGGG repeat and negatively regulates telomere length. Involved in the regulation of the mitotic spindle. 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.[1] [FBX4_HUMAN] Substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex that mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Promotes ubiquitination of CCND1 and its subsequent proteasomal degradation. Recognizes TERF1 and promotes its ubiquitination together with UBE2D1.[2] [3] [4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTRF1 is a critical regulator of telomere length. As such, TRF1 levels are regulated by ubiquitin-dependent proteolysis via an SCF E3 ligase where Fbx4 contributes to substrate specification. Here, we report the crystal structure of the Fbx4-TRF1 complex at 2.4 A resolution. Fbx4 contains an unusual substrate-binding domain that adopts a small GTPase fold. Strikingly, this atypical GTPase domain of Fbx4 binds to a globular domain of TRF1 through an intermolecular beta sheet, instead of recognizing short peptides/degrons as often seen in other F-box protein-substrate complexes. Importantly, mutations in this interface abrogate Fbx4-dependent TRF1 binding and ubiquitination. Furthermore, the data demonstrate that recognition of TRF1 by SCF(Fbx4) is regulated by another telomere protein, TIN2. Our results reveal an atypical small GTPase domain within Fbx4 as a substrate-binding motif for SCF(Fbx4) and uncover a mechanism for selective ubiquitination and degradation of TRF1 in telomere homeostasis control. Structural basis of selective ubiquitination of TRF1 by SCFFbx4.,Zeng Z, Wang W, Yang Y, Chen Y, Yang X, Diehl JA, Liu X, Lei M Dev Cell. 2010 Feb 16;18(2):214-25. PMID:20159592[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | Chen, Y | Diehl, J A | Lei, M | Liu, X D | Wang, W | Yang, X M | Yang, Y T | Zeng, Z X | Adp-ribosylation | Cell cycle | Cell division | Chromosomal protein | Cytoskeleton | Dna-binding | Gtpase domain | Helix | Mitosis | Nucleus | Phosphoprotein | Telomere | Trfh domain | Ubl conjugation pathway
