| Structural highlights
9fib is a 10 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | Electron Microscopy, Resolution 2.3Å |
| Ligands: | , , , , , , , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
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 bacterial translation initiation, the 30S ribosomal subunit, initiation factors, and initiator tRNA define the reading frame of the mRNA. This process is inhibited by kasugamycin, edeine and GE81112, however, their mechanisms of action have not been fully elucidated. Here we present cryo-electron microscopy structures of 30S initiation intermediate complexes formed in the presence of kasugamycin, edeine and GE81112 at resolutions of 2.0-2.9 A. The structures reveal that all three antibiotics bind within the E-site of the 30S and preclude 30S initiation complex formation. While kasugamycin and edeine affect early steps of 30S pre-initiation complex formation, GE81112 stalls pre-initiation complex formation at a further step by allowing start codon recognition, but impeding IF3 departure. Collectively, our work highlights how chemically distinct compounds binding at a conserved site on the 30S can interfere with translation initiation in a unique manner.
The translation inhibitors kasugamycin, edeine and GE81112 target distinct steps during 30S initiation complex formation.,Safdari HA, Morici M, Sanchez-Castro A, Dallape A, Paternoga H, Giuliodori AM, Fabbretti A, Milon P, Wilson DN Nat Commun. 2025 Mar 12;16(1):2470. doi: 10.1038/s41467-025-57731-8. PMID:40075065[16]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
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
- ↑ Safdari HA, Morici M, Sanchez-Castro A, Dallapè A, Paternoga H, Giuliodori AM, Fabbretti A, Milón P, Wilson DN. The translation inhibitors kasugamycin, edeine and GE81112 target distinct steps during 30S initiation complex formation. Nat Commun. 2025 Mar 12;16(1):2470. PMID:40075065 doi:10.1038/s41467-025-57731-8
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