| Structural highlights
Function
RS4_ECOLI One of two assembly initiator proteins for the 30S subunit, it binds directly to 16S rRNA where it nucleates assembly of the body of the 30S subunit.[1] [2] [3] With S5 and S12 plays an important role in translational accuracy; many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations).[4] [5] [6] Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp.[7] [8] [9] Protein S4 is also a translational repressor protein, it controls the translation of the alpha-operon (which codes for S13, S11, S4, RNA polymerase alpha subunit, and L17) by binding to its mRNA.[10] [11] [12] Also functions as a rho-dependent antiterminator of rRNA transcription, increasing the synthesis of rRNA under conditions of excess protein, allowing a more rapid return to homeostasis. Binds directly to RNA polymerase.[13] [14] [15]
Publication Abstract from PubMed
During 30S ribosomal subunit biogenesis, assembly factors are believed to prevent accumulation of misfolded intermediate states of low free energy that slowly convert into mature 30S subunits, namely, kinetically trapped particles. Among the assembly factors, the circularly permuted GTPase, RsgA, plays a crucial role in the maturation of the 30S decoding center. Here, directed hydroxyl radical probing and single particle cryo-EM are employed to elucidate RsgA's mechanism of action. Our results show that RsgA destabilizes the 30S structure, including late binding r-proteins, providing a structural basis for avoiding kinetically trapped assembly intermediates. Moreover, RsgA exploits its distinct GTPase pocket and specific interactions with the 30S to coordinate GTPase activation with the maturation state of the 30S subunit. This coordination validates the architecture of the decoding center and facilitates the timely release of RsgA to control the progression of 30S biogenesis.
RsgA couples the maturation state of the 30S ribosomal decoding center to activation of its GTPase pocket.,Lopez-Alonso JP, Kaminishi T, Kikuchi T, Hirata Y, Iturrioz I, Dhimole N, Schedlbauer A, Hase Y, Goto S, Kurita D, Muto A, Zhou S, Naoe C, Mills DJ, Gil-Carton D, Takemoto C, Himeno H, Fucini P, Connell SR Nucleic Acids Res. 2017 May 8. doi: 10.1093/nar/gkx324. PMID:28482099[16]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Nowotny V, Nierhaus KH. Assembly of the 30S subunit from Escherichia coli ribosomes occurs via two assembly domains which are initiated by S4 and S7. Biochemistry. 1988 Sep 6;27(18):7051-5. PMID:2461734
- ↑ Torres M, Condon C, Balada JM, Squires C, Squires CL. Ribosomal protein S4 is a transcription factor with properties remarkably similar to NusA, a protein involved in both non-ribosomal and ribosomal RNA antitermination. EMBO J. 2001 Jul 16;20(14):3811-20. PMID:11447122 doi:10.1093/emboj/20.14.3811
- ↑ Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
- ↑ Nowotny V, Nierhaus KH. Assembly of the 30S subunit from Escherichia coli ribosomes occurs via two assembly domains which are initiated by S4 and S7. Biochemistry. 1988 Sep 6;27(18):7051-5. PMID:2461734
- ↑ Torres M, Condon C, Balada JM, Squires C, Squires CL. Ribosomal protein S4 is a transcription factor with properties remarkably similar to NusA, a protein involved in both non-ribosomal and ribosomal RNA antitermination. EMBO J. 2001 Jul 16;20(14):3811-20. PMID:11447122 doi:10.1093/emboj/20.14.3811
- ↑ Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
- ↑ Nowotny V, Nierhaus KH. Assembly of the 30S subunit from Escherichia coli ribosomes occurs via two assembly domains which are initiated by S4 and S7. Biochemistry. 1988 Sep 6;27(18):7051-5. PMID:2461734
- ↑ Torres M, Condon C, Balada JM, Squires C, Squires CL. Ribosomal protein S4 is a transcription factor with properties remarkably similar to NusA, a protein involved in both non-ribosomal and ribosomal RNA antitermination. EMBO J. 2001 Jul 16;20(14):3811-20. PMID:11447122 doi:10.1093/emboj/20.14.3811
- ↑ Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
- ↑ Nowotny V, Nierhaus KH. Assembly of the 30S subunit from Escherichia coli ribosomes occurs via two assembly domains which are initiated by S4 and S7. Biochemistry. 1988 Sep 6;27(18):7051-5. PMID:2461734
- ↑ Torres M, Condon C, Balada JM, Squires C, Squires CL. Ribosomal protein S4 is a transcription factor with properties remarkably similar to NusA, a protein involved in both non-ribosomal and ribosomal RNA antitermination. EMBO J. 2001 Jul 16;20(14):3811-20. PMID:11447122 doi:10.1093/emboj/20.14.3811
- ↑ Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
- ↑ Nowotny V, Nierhaus KH. Assembly of the 30S subunit from Escherichia coli ribosomes occurs via two assembly domains which are initiated by S4 and S7. Biochemistry. 1988 Sep 6;27(18):7051-5. PMID:2461734
- ↑ Torres M, Condon C, Balada JM, Squires C, Squires CL. Ribosomal protein S4 is a transcription factor with properties remarkably similar to NusA, a protein involved in both non-ribosomal and ribosomal RNA antitermination. EMBO J. 2001 Jul 16;20(14):3811-20. PMID:11447122 doi:10.1093/emboj/20.14.3811
- ↑ Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
- ↑ Lopez-Alonso JP, Kaminishi T, Kikuchi T, Hirata Y, Iturrioz I, Dhimole N, Schedlbauer A, Hase Y, Goto S, Kurita D, Muto A, Zhou S, Naoe C, Mills DJ, Gil-Carton D, Takemoto C, Himeno H, Fucini P, Connell SR. RsgA couples the maturation state of the 30S ribosomal decoding center to activation of its GTPase pocket. Nucleic Acids Res. 2017 May 8. doi: 10.1093/nar/gkx324. PMID:28482099 doi:http://dx.doi.org/10.1093/nar/gkx324
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