| Structural highlights
Function
[RRP1_YEAST] Required for 27S rRNA processing to 25S and 5.8S. [RL37A_YEAST] Binds to the 23S rRNA (By similarity). [NOP15_YEAST] Involved in the biogenesis of the 60S ribosomal subunit. Required for pre-rRNA processing and cytokinesis. Associates with the precursors of the 25S and 5.8S rRNAs.[1] [2] [NOP16_YEAST] Involved in the biogenesis of the 60S ribosomal subunit.[3] [BRX1_YEAST] Required for biogenesis of the 60S ribosomal subunit.[4] [RLP7_YEAST] Involved in the biogenesis of the 60S ribosomal subunit. May act as a specificity factor that binds precursor rRNAs and tethers the enzymes that carry out the early 5' to 3' exonucleolytic reactions that generate the mature rRNAs.[5] [ERB1_YEAS7] Component of the NOP7 complex, which is required for maturation of the 25S and 5.8S ribosomal RNAs and formation of the 60S ribosome.[HAMAP-Rule:MF_03027]
Publication Abstract from PubMed
Early co-transcriptional events of eukaryotic ribosome assembly result in the formation of precursors of the small (40S) and large (60S) ribosomal subunits(1). A multitude of transient assembly factors regulate and chaperone the systematic folding of pre-ribosomal RNA subdomains. However, due to limited structural information, the role of these factors during early nucleolar 60S assembly is not fully understood. Here we have determined cryo-EM reconstructions of the nucleolar pre-60S ribosomal subunit in different conformational states at resolutions up to 3.4 A. These reconstructions reveal how steric hindrance and molecular mimicry are used to prevent both premature folding states and binding of later factors. This is accomplished by the concerted activity of 21 ribosome assembly factors that stabilize and remodel pre-ribosomal RNA and ribosomal proteins. Among these factors, three Brix-domain proteins and their binding partners form a ring-like structure at rRNA domain boundaries to support the architecture of the maturing particle. Mutually exclusive conformations of these pre-60S particles suggest that the formation of the polypeptide exit tunnel is achieved through different folding pathways during subsequent stages of ribosome assembly. These structures rationalize previous genetic and biochemical data and highlight the mechanisms driving eukaryotic ribosome assembly in a unidirectional manner.
Modular assembly of the nucleolar pre-60S ribosomal subunit.,Sanghai ZA, Miller L, Molloy KR, Barandun J, Hunziker M, Chaker-Margot M, Wang J, Chait BT, Klinge S Nature. 2018 Mar 5. pii: nature26156. doi: 10.1038/nature26156. PMID:29512650[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Harnpicharnchai P, Jakovljevic J, Horsey E, Miles T, Roman J, Rout M, Meagher D, Imai B, Guo Y, Brame CJ, Shabanowitz J, Hunt DF, Woolford JL Jr. Composition and functional characterization of yeast 66S ribosome assembly intermediates. Mol Cell. 2001 Sep;8(3):505-15. PMID:11583614
- ↑ Oeffinger M, Tollervey D. Yeast Nop15p is an RNA-binding protein required for pre-rRNA processing and cytokinesis. EMBO J. 2003 Dec 15;22(24):6573-83. PMID:14657029 doi:http://dx.doi.org/10.1093/emboj/cdg616
- ↑ Harnpicharnchai P, Jakovljevic J, Horsey E, Miles T, Roman J, Rout M, Meagher D, Imai B, Guo Y, Brame CJ, Shabanowitz J, Hunt DF, Woolford JL Jr. Composition and functional characterization of yeast 66S ribosome assembly intermediates. Mol Cell. 2001 Sep;8(3):505-15. PMID:11583614
- ↑ Kaser A, Bogengruber E, Hallegger M, Doppler E, Lepperdinger G, Jantsch M, Breitenbach M, Kreil G. Brix from xenopus laevis and brx1p from yeast define a new family of proteins involved in the biogenesis of large ribosomal subunits. Biol Chem. 2001 Dec;382(12):1637-47. doi: 10.1515/BC.2001.199. PMID:11843177 doi:http://dx.doi.org/10.1515/BC.2001.199
- ↑ Dunbar DA, Dragon F, Lee SJ, Baserga SJ. A nucleolar protein related to ribosomal protein L7 is required for an early step in large ribosomal subunit biogenesis. Proc Natl Acad Sci U S A. 2000 Nov 21;97(24):13027-32. PMID:11087857 doi:http://dx.doi.org/10.1073/pnas.97.24.13027
- ↑ Sanghai ZA, Miller L, Molloy KR, Barandun J, Hunziker M, Chaker-Margot M, Wang J, Chait BT, Klinge S. Modular assembly of the nucleolar pre-60S ribosomal subunit. Nature. 2018 Mar 5. pii: nature26156. doi: 10.1038/nature26156. PMID:29512650 doi:http://dx.doi.org/10.1038/nature26156
|
