| Structural highlights
Function
[SUS1_YEAST] Involved in mRNA export coupled transcription activation by association with both the TREX-2 and the SAGA complexes. The transcription regulatory histone acetylation (HAT) complex SAGA is involved in RNA polymerase II-dependent regulation of approximately 10% of yeast genes. At the promoters, SAGA is required for recruitment of the basal transcription machinery. It influences RNA polymerase II transcriptional activity through different activities such as TBP interaction (SPT3, SPT8 and SPT20) and promoter selectivity, interaction with transcription activators (GCN5, ADA2, ADA3 and TRA1), and chromatin modification through histone acetylation (GCN5) and deubiquitination (UBP8). SUS1 forms a distinct functional SAGA module with UBP8, SGF11 and SGF73 required for deubiquitination of H2B and for the maintenance of steady-state H3 methylation levels. The TREX-2 complex functions in docking export-competent ribonucleoprotein particles (mRNPs) to the nuclear entrance of the nuclear pore complex (nuclear basket), by association with components of the nuclear mRNA export machinery (MEX67-MTR2 and SUB2) in the nucleoplasm and the nucleoporin NUP1 at the nuclear basket. TREX-2 participates in mRNA export and accurate chromatin positioning in the nucleus by tethering genes to the nuclear periphery. SUS1 has also a role in mRNP biogenesis and maintenance of genome integrity through preventing RNA-mediated genome instability. Finally SUS1 has a role in response to DNA damage induced by methyl methane sulfonate (MMS) and replication arrest induced by hydroxyurea.[1] [2] [3] [4] [5] [6] [7] [SGF11_YEAST] Component of the transcription regulatory histone acetylation (HAT) complex SAGA. SAGA is involved in RNA polymerase II-dependent transcriptional regulation of approximately 10% of yeast genes. At the promoters, SAGA is required for recruitment of the basal transcription machinery. It influences RNA polymerase II transcriptional activity through different activities such as TBP interaction (SPT3, SPT8 and SPT20) and promoter selectivity, interaction with transcription activators (GCN5, ADA2, ADA3 and TRA1), and chromatin modification through histone acetylation (GCN5) and deubiquitination (UBP8). SAGA acetylates nucleosomal histone H3 to some extent (to form H3K9ac, H3K14ac, H3K18ac and H3K23ac). SAGA interacts with DNA via upstream activating sequences (UASs). SGF11 is involved in transcriptional regulation of a subset of SAGA-regulated genes. Within the SAGA complex, participates in a subcomplex with SUS1, SGF73 and UBP8 required for deubiquitination of H2B and for the maintenance of steady-state H3 methylation levels. It is required to recruit UBP8 and SUS1 into the SAGA complex.[8] [9]
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 PubMed
Sus1 is a central component of the yeast gene gating machinery, the process by which actively transcribing genes such as GAL1 become associated with nuclear pore complexes. Sus1 is a component of both the SAGA transcriptional co-activator complex and the TREX-2 complex that binds to nuclear pore complexes. TREX-2 contains two Sus1 chains that have an articulated helical hairpin fold, enabling them to wrap around an extended alpha-helix in Sac3, following a helical hydrophobic stripe. In SAGA, Sus1 binds to Sgf11 and has been proposed to provide a link between SAGA and TREX-2. We present here the crystal structure of the complex between Sus1 and the N-terminal region of Sgf11 that forms an extended alpha-helix around which Sus1 wraps in a manner that shares some similarities with the Sus1-Sac3 interface in TREX-2. However, the Sus1-binding site on Sgf11 is somewhat shorter than on Sac3 and is based on a narrower hydrophobic stripe. Engineered mutants that disrupt the Sgf11-Sus1 interaction in vitro confirm the importance of the hydrophobic helical stripe in molecular recognition. Helix alpha1 of the Sus1-articulated hairpin does not bind directly to Sgf11 and adopts a wide range of conformations within and between crystal forms, consistent with the presence of a flexible hinge and also with results from previous extensive mutagenesis studies (Klockner, C., Schneider, M., Lutz, S., Jani, D., Kressler, D., Stewart, M., Hurt, E., and Kohler, A. (2009) J. Biol. Chem. 284, 12049-12056). A single Sus1 molecule cannot bind Sgf11 and Sac3 simultaneously and this, combined with the structure of the Sus1-Sgf11 complex, indicates that Sus1 forms separate subcomplexes within SAGA and TREX-2.
Structural basis for the interaction between yeast Spt-Ada-Gcn5 acetyltransferase (SAGA) complex components Sgf11 and Sus1.,Ellisdon AM, Jani D, Kohler A, Hurt E, Stewart M J Biol Chem. 2010 Feb 5;285(6):3850-6. Epub 2009 Dec 9. PMID:20007317[10]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Fischer T, Rodriguez-Navarro S, Pereira G, Racz A, Schiebel E, Hurt E. Yeast centrin Cdc31 is linked to the nuclear mRNA export machinery. Nat Cell Biol. 2004 Sep;6(9):840-8. Epub 2004 Aug 15. PMID:15311284 doi:10.1038/ncb1163
- ↑ Kastenmayer JP, Ni L, Chu A, Kitchen LE, Au WC, Yang H, Carter CD, Wheeler D, Davis RW, Boeke JD, Snyder MA, Basrai MA. Functional genomics of genes with small open reading frames (sORFs) in S. cerevisiae. Genome Res. 2006 Mar;16(3):365-73. PMID:16510898 doi:16/3/365
- ↑ Kohler A, Pascual-Garcia P, Llopis A, Zapater M, Posas F, Hurt E, Rodriguez-Navarro S. The mRNA export factor Sus1 is involved in Spt/Ada/Gcn5 acetyltransferase-mediated H2B deubiquitinylation through its interaction with Ubp8 and Sgf11. Mol Biol Cell. 2006 Oct;17(10):4228-36. Epub 2006 Jul 19. PMID:16855026 doi:E06-02-0098
- ↑ Cabal GG, Genovesio A, Rodriguez-Navarro S, Zimmer C, Gadal O, Lesne A, Buc H, Feuerbach-Fournier F, Olivo-Marin JC, Hurt EC, Nehrbass U. SAGA interacting factors confine sub-diffusion of transcribed genes to the nuclear envelope. Nature. 2006 Jun 8;441(7094):770-3. PMID:16760982 doi:10.1038/nature04752
- ↑ Pascual-Garcia P, Govind CK, Queralt E, Cuenca-Bono B, Llopis A, Chavez S, Hinnebusch AG, Rodriguez-Navarro S. Sus1 is recruited to coding regions and functions during transcription elongation in association with SAGA and TREX2. Genes Dev. 2008 Oct 15;22(20):2811-22. doi: 10.1101/gad.483308. PMID:18923079 doi:10.1101/gad.483308
- ↑ Gonzalez-Aguilera C, Tous C, Gomez-Gonzalez B, Huertas P, Luna R, Aguilera A. The THP1-SAC3-SUS1-CDC31 complex works in transcription elongation-mRNA export preventing RNA-mediated genome instability. Mol Biol Cell. 2008 Oct;19(10):4310-8. doi: 10.1091/mbc.E08-04-0355. Epub 2008, Jul 30. PMID:18667528 doi:10.1091/mbc.E08-04-0355
- ↑ Chekanova JA, Abruzzi KC, Rosbash M, Belostotsky DA. Sus1, Sac3, and Thp1 mediate post-transcriptional tethering of active genes to the nuclear rim as well as to non-nascent mRNP. RNA. 2008 Jan;14(1):66-77. Epub 2007 Nov 14. PMID:18003937 doi:10.1261/rna.764108
- ↑ Ingvarsdottir K, Krogan NJ, Emre NC, Wyce A, Thompson NJ, Emili A, Hughes TR, Greenblatt JF, Berger SL. H2B ubiquitin protease Ubp8 and Sgf11 constitute a discrete functional module within the Saccharomyces cerevisiae SAGA complex. Mol Cell Biol. 2005 Feb;25(3):1162-72. PMID:15657441 doi:25/3/1162
- ↑ Lee KK, Florens L, Swanson SK, Washburn MP, Workman JL. The deubiquitylation activity of Ubp8 is dependent upon Sgf11 and its association with the SAGA complex. Mol Cell Biol. 2005 Feb;25(3):1173-82. PMID:15657442 doi:http://dx.doi.org/10.1128/MCB.25.3.1173-1182.2005
- ↑ Ellisdon AM, Jani D, Kohler A, Hurt E, Stewart M. Structural basis for the interaction between yeast Spt-Ada-Gcn5 acetyltransferase (SAGA) complex components Sgf11 and Sus1. J Biol Chem. 2010 Feb 5;285(6):3850-6. Epub 2009 Dec 9. PMID:20007317 doi:10.1074/jbc.M109.070839
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