30S ribosomal protein S4


30S ribosomal protein S4
  • ramA
Gene Name
Escherichia coli (strain K12)
Amino acid sequence
>lcl|BSEQ0009877|30S ribosomal protein S4
Number of residues
Molecular Weight
Theoretical pI
GO Classification
mRNA 5'-UTR binding / rRNA binding / structural constituent of ribosome / translation repressor activity, nucleic acid binding
DNA-templated transcription, termination / maintenance of translational fidelity / negative regulation of translational initiation / positive regulation of translational fidelity / response to antibiotic / transcription antitermination
cytosol / cytosolic small ribosomal subunit
General Function
Translation repressor activity, nucleic acid binding
Specific Function
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.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).Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp.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.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.
Pfam Domain Function
Transmembrane Regions
Not Available
Cellular Location
Gene sequence
>lcl|BSEQ0009878|30S ribosomal protein S4 (rpsD)
Chromosome Location
Not Available
Not Available
External Identifiers
UniProtKB IDP0A7V8
UniProtKB Entry NameRS4_ECOLI
GenBank Protein ID42798
GenBank Gene IDX02543
General References
  1. Bedwell D, Davis G, Gosink M, Post L, Nomura M, Kestler H, Zengel JM, Lindahl L: Nucleotide sequence of the alpha ribosomal protein operon of Escherichia coli. Nucleic Acids Res. 1985 Jun 11;13(11):3891-903. [Article]
  2. Blattner FR, Plunkett G 3rd, Bloch CA, Perna NT, Burland V, Riley M, Collado-Vides J, Glasner JD, Rode CK, Mayhew GF, Gregor J, Davis NW, Kirkpatrick HA, Goeden MA, Rose DJ, Mau B, Shao Y: The complete genome sequence of Escherichia coli K-12. Science. 1997 Sep 5;277(5331):1453-62. [Article]
  3. Hayashi K, Morooka N, Yamamoto Y, Fujita K, Isono K, Choi S, Ohtsubo E, Baba T, Wanner BL, Mori H, Horiuchi T: Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110. Mol Syst Biol. 2006;2:2006.0007. Epub 2006 Feb 21. [Article]
  4. Reinbolt J, Schiltz E: The primary structure of ribosomal protein S4 from Escherichia coli. FEBS Lett. 1973 Nov 1;36(3):250-2. [Article]
  5. Schiltz E, Reinbolt J: Determination of the complete amino-acid sequence of protein S4 from Escherichia coli ribosomes. Eur J Biochem. 1975 Aug 15;56(2):467-81. [Article]
  6. Urlaub H, Kruft V, Bischof O, Muller EC, Wittmann-Liebold B: Protein-rRNA binding features and their structural and functional implications in ribosomes as determined by cross-linking studies. EMBO J. 1995 Sep 15;14(18):4578-88. [Article]
  7. Post LE, Nomura M: Nucleotide sequence of the intercistronic region preceding the gene for RNA polymerase subunit alpha in Escherichia coli. J Biol Chem. 1979 Nov 10;254(21):10604-6. [Article]
  8. Thomas MS, Bedwell DM, Nomura M: Regulation of alpha operon gene expression in Escherichia coli. A novel form of translational coupling. J Mol Biol. 1987 Jul 20;196(2):333-45. [Article]
  9. 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. [Article]
  10. Allen PN, Noller HF: Mutations in ribosomal proteins S4 and S12 influence the higher order structure of 16 S ribosomal RNA. J Mol Biol. 1989 Aug 5;208(3):457-68. [Article]
  11. Baker AM, Draper DE: Messenger RNA recognition by fragments of ribosomal protein S4. J Biol Chem. 1995 Sep 29;270(39):22939-45. [Article]
  12. Choi KM, Atkins JF, Gesteland RF, Brimacombe R: Flexibility of the nascent polypeptide chain within the ribosome--contacts from the peptide N-terminus to a specific region of the 30S subunit. Eur J Biochem. 1998 Jul 15;255(2):409-13. [Article]
  13. Dahlgren A, Ryden-Aulin M: A novel mutation in ribosomal protein S4 that affects the function of a mutated RF1. Biochimie. 2000 Aug;82(8):683-91. [Article]
  14. 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. [Article]
  15. Takyar S, Hickerson RP, Noller HF: mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. [Article]
  16. Arnold RJ, Reilly JP: Observation of Escherichia coli ribosomal proteins and their posttranslational modifications by mass spectrometry. Anal Biochem. 1999 Apr 10;269(1):105-12. [Article]
  17. Tung CS, Joseph S, Sanbonmatsu KY: All-atom homology model of the Escherichia coli 30S ribosomal subunit. Nat Struct Biol. 2002 Oct;9(10):750-5. [Article]
  18. Gao H, Sengupta J, Valle M, Korostelev A, Eswar N, Stagg SM, Van Roey P, Agrawal RK, Harvey SC, Sali A, Chapman MS, Frank J: Study of the structural dynamics of the E coli 70S ribosome using real-space refinement. Cell. 2003 Jun 13;113(6):789-801. [Article]
  19. Schuwirth BS, Borovinskaya MA, Hau CW, Zhang W, Vila-Sanjurjo A, Holton JM, Cate JH: Structures of the bacterial ribosome at 3.5 A resolution. Science. 2005 Nov 4;310(5749):827-34. [Article]

Drug Relations

Drug Relations
DrugBank IDNameDrug groupPharmacological action?ActionsDetails
DB00595Oxytetracyclineapproved, investigational, vet_approvedyesinhibitorDetails
DB01017Minocyclineapproved, investigationalyesinhibitorDetails
DB12329Eravacyclineapproved, investigationalyesinhibitorDetails
DB00256Lymecyclineapproved, investigationalyesinhibitorDetails