| Structural highlights
Function
SUV3_HUMAN Major helicase player in mitochondrial RNA metabolism. Component of the mitochondrial degradosome (mtEXO) complex, that degrades 3' overhang double-stranded RNA with a 3'-to-5' directionality in an ATP-dependent manner. ATPase and ATP-dependent multisubstrate helicase, able to unwind double-stranded (ds) DNA and RNA, and RNA/DNA heteroduplexes in the 5'-to-3' direction. Plays a role in the RNA surveillance system in mitochondria; regulates the stability of mature mRNAs, the removal of aberrantly formed mRNAs and the rapid degradation of non coding processing intermediates. Also implicated in recombination and chromatin maintenance pathways. May protect cells from apoptosis. Associates with mitochondrial DNA.[1] [2] [3] [4] [5] [6] [7]
Publication Abstract from PubMed
Human Suv3 is a dimeric helicase that collaborates with the exoribonuclease PNPase to mediate RNA decay and surveillance in mitochondria. Despite its pivotal role in maintaining mitochondrial homeostasis, the molecular mechanism underlying Suv3-mediated RNA unwinding has remained elusive. Here, we present near-atomic-resolution cryogenic electron microscopy structures of Suv3 captured in four functional states: the apo form, two binary complexes with ADP and single-stranded RNA (ssRNA), and a ternary complex with ssRNA and an ATP analog (AMP-PNP). These structures reveal an unexpected asymmetric dimeric organization, in which only one of the two protomers engages in the initial binding of ADP, ssRNA, or both ssRNA and AMP-PNP. Complementary biochemical analyses demonstrate that Suv3 dimerization significantly enhances RNA-binding and unwinding efficiency in an ATP-hydrolysis-dependent manner. Together, these findings provide key insights into the dimeric architecture of Suv3 and establish a mechanistic framework for its coordinated function in processive RNA unwinding.
Asymmetric dimeric assembly of Suv3 helicase facilitates processive RNA unwinding.,Patra M, Jain M, Li YC, Chen YP, Golzarroshan B, Yuan HS Nat Commun. 2026 Apr 15. doi: 10.1038/s41467-026-71901-2. PMID:41986356[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Minczuk M, Piwowarski J, Papworth MA, Awiszus K, Schalinski S, Dziembowski A, Dmochowska A, Bartnik E, Tokatlidis K, Stepien PP, Borowski P. Localisation of the human hSuv3p helicase in the mitochondrial matrix and its preferential unwinding of dsDNA. Nucleic Acids Res. 2002 Dec 1;30(23):5074-86. PMID:12466530
- ↑ Shu Z, Vijayakumar S, Chen CF, Chen PL, Lee WH. Purified human SUV3p exhibits multiple-substrate unwinding activity upon conformational change. Biochemistry. 2004 Apr 27;43(16):4781-90. PMID:15096047 doi:https://dx.doi.org/10.1021/bi0356449
- ↑ Szczesny RJ, Obriot H, Paczkowska A, Jedrzejczak R, Dmochowska A, Bartnik E, Formstecher P, Polakowska R, Stepien PP. Down-regulation of human RNA/DNA helicase SUV3 induces apoptosis by a caspase- and AIF-dependent pathway. Biol Cell. 2007 Jun;99(6):323-32. PMID:17352692 doi:https://dx.doi.org/BC20060108
- ↑ Pereira M, Mason P, Szczesny RJ, Maddukuri L, Dziwura S, Jedrzejczak R, Paul E, Wojcik A, Dybczynska L, Tudek B, Bartnik E, Klysik J, Bohr VA, Stepien PP. Interaction of human SUV3 RNA/DNA helicase with BLM helicase; loss of the SUV3 gene results in mouse embryonic lethality. Mech Ageing Dev. 2007 Nov-Dec;128(11-12):609-17. Epub 2007 Sep 14. PMID:17961633 doi:https://dx.doi.org/10.1016/j.mad.2007.09.001
- ↑ Khidr L, Wu G, Davila A, Procaccio V, Wallace D, Lee WH. Role of SUV3 helicase in maintaining mitochondrial homeostasis in human cells. J Biol Chem. 2008 Oct 3;283(40):27064-73. doi: 10.1074/jbc.M802991200. Epub 2008 , Aug 4. PMID:18678873 doi:https://dx.doi.org/10.1074/jbc.M802991200
- ↑ Wang DD, Shu Z, Lieser SA, Chen PL, Lee WH. Human mitochondrial SUV3 and polynucleotide phosphorylase form a 330-kDa heteropentamer to cooperatively degrade double-stranded RNA with a 3'-to-5' directionality. J Biol Chem. 2009 Jul 31;284(31):20812-21. Epub 2009 Jun 9. PMID:19509288 doi:M109.009605
- ↑ Szczesny RJ, Borowski LS, Brzezniak LK, Dmochowska A, Gewartowski K, Bartnik E, Stepien PP. Human mitochondrial RNA turnover caught in flagranti: involvement of hSuv3p helicase in RNA surveillance. Nucleic Acids Res. 2010 Jan;38(1):279-98. Epub 2009 Oct 28. PMID:19864255 doi:https://dx.doi.org/gkp903
- ↑ Patra M, Jain M, Li YC, Chen YP, Golzarroshan B, Yuan HS. Asymmetric dimeric assembly of Suv3 helicase facilitates processive RNA unwinding. Nat Commun. 2026 Apr 15. PMID:41986356 doi:10.1038/s41467-026-71901-2
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