| Structural highlights
Function
SKI2_YEAST RNA helicase component of the SKI complex involved in 3'-mRNA degradation pathway. Represses dsRNA virus propagation by specifically blocking translation of viral mRNAs, perhaps recognizing the absence of CAP or poly(A). Essential for cell growth only in the presence of M1 replicon.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]
Publication Abstract from PubMed
The Ski complex is a conserved multiprotein assembly required for the cytoplasmic functions of the exosome, including RNA turnover, surveillance, and interference. Ski2, Ski3, and Ski8 assemble in a tetramer with 1:1:2 stoichiometry. The crystal structure of an S. cerevisiae 370 kDa core complex shows that Ski3 forms an array of 33 TPR motifs organized in N-terminal and C-terminal arms. The C-terminal arm of Ski3 and the two Ski8 subunits position the helicase core of Ski2 centrally within the complex, enhancing RNA binding. The Ski3 N-terminal arm and the Ski2 insertion domain allosterically modulate the ATPase and helicase activities of the complex. Biochemical data suggest that the Ski complex can thread RNAs directly to the exosome, coupling the helicase and the exoribonuclease through a continuous RNA channel. Finally, we identify a Ski8-binding motif common to Ski3 and Spo11, rationalizing the moonlighting properties of Ski8 in mRNA decay and meiosis.
The yeast ski complex: crystal structure and RNA channeling to the exosome complex.,Halbach F, Reichelt P, Rode M, Conti E Cell. 2013 Aug 15;154(4):814-26. doi: 10.1016/j.cell.2013.07.017. PMID:23953113[14]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Widner WR, Wickner RB. Evidence that the SKI antiviral system of Saccharomyces cerevisiae acts by blocking expression of viral mRNA. Mol Cell Biol. 1993 Jul;13(7):4331-41. PMID:8321235
- ↑ Toh-E A, Guerry P, Wickner RB. Chromosomal superkiller mutants of Saccharomyces cerevisiae. J Bacteriol. 1978 Dec;136(3):1002-7. PMID:363683
- ↑ Ridley SP, Sommer SS, Wickner RB. Superkiller mutations in Saccharomyces cerevisiae suppress exclusion of M2 double-stranded RNA by L-A-HN and confer cold sensitivity in the presence of M and L-A-HN. Mol Cell Biol. 1984 Apr;4(4):761-70. PMID:6371496
- ↑ Johnson AW, Kolodner RD. Synthetic lethality of sep1 (xrn1) ski2 and sep1 (xrn1) ski3 mutants of Saccharomyces cerevisiae is independent of killer virus and suggests a general role for these genes in translation control. Mol Cell Biol. 1995 May;15(5):2719-27. PMID:7739552
- ↑ Masison DC, Blanc A, Ribas JC, Carroll K, Sonenberg N, Wickner RB. Decoying the cap- mRNA degradation system by a double-stranded RNA virus and poly(A)- mRNA surveillance by a yeast antiviral system. Mol Cell Biol. 1995 May;15(5):2763-71. PMID:7739557
- ↑ Anderson JS, Parker RP. The 3' to 5' degradation of yeast mRNAs is a general mechanism for mRNA turnover that requires the SKI2 DEVH box protein and 3' to 5' exonucleases of the exosome complex. EMBO J. 1998 Mar 2;17(5):1497-506. PMID:9482746 doi:10.1093/emboj/17.5.1497
- ↑ van Hoof A, Lennertz P, Parker R. Yeast exosome mutants accumulate 3'-extended polyadenylated forms of U4 small nuclear RNA and small nucleolar RNAs. Mol Cell Biol. 2000 Jan;20(2):441-52. PMID:10611222
- ↑ Brown JT, Bai X, Johnson AW. The yeast antiviral proteins Ski2p, Ski3p, and Ski8p exist as a complex in vivo. RNA. 2000 Mar;6(3):449-57. PMID:10744028
- ↑ Searfoss AM, Wickner RB. 3' poly(A) is dispensable for translation. Proc Natl Acad Sci U S A. 2000 Aug 1;97(16):9133-7. PMID:10922069
- ↑ Araki Y, Takahashi S, Kobayashi T, Kajiho H, Hoshino S, Katada T. Ski7p G protein interacts with the exosome and the Ski complex for 3'-to-5' mRNA decay in yeast. EMBO J. 2001 Sep 3;20(17):4684-93. PMID:11532933 doi:10.1093/emboj/20.17.4684
- ↑ Brown JT, Johnson AW. A cis-acting element known to block 3' mRNA degradation enhances expression of polyA-minus mRNA in wild-type yeast cells and phenocopies a ski mutant. RNA. 2001 Nov;7(11):1566-77. PMID:11720286
- ↑ Mitchell P, Tollervey D. An NMD pathway in yeast involving accelerated deadenylation and exosome-mediated 3'-->5' degradation. Mol Cell. 2003 May;11(5):1405-13. PMID:12769863
- ↑ Kushner DB, Lindenbach BD, Grdzelishvili VZ, Noueiry AO, Paul SM, Ahlquist P. Systematic, genome-wide identification of host genes affecting replication of a positive-strand RNA virus. Proc Natl Acad Sci U S A. 2003 Dec 23;100(26):15764-9. Epub 2003 Dec 11. PMID:14671320 doi:10.1073/pnas.2536857100
- ↑ Halbach F, Reichelt P, Rode M, Conti E. The yeast ski complex: crystal structure and RNA channeling to the exosome complex. Cell. 2013 Aug 15;154(4):814-26. doi: 10.1016/j.cell.2013.07.017. PMID:23953113 doi:10.1016/j.cell.2013.07.017
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