Gene Symbol: rsmA
Description: 16S rRNA m(6)A1518, m(6)A1519 dimethyltransferase, SAM-dependent
Alias: ECK0052, JW0050, ksgA
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. van Gemen B, Koets H, Plooy C, Bodlaender J, Van Knippenberg P. Characterization of the ksgA gene of Escherichia coli determining kasugamycin sensitivity. Biochimie. 1987;69:841-8 pubmed
    In the plasmid pUC8ksgA7, the coding region of the ksgA gene is preceded by the lac promoter (Plac) and a small open reading frame (ORF)...
  2. van Buul C, Van Knippenberg P. Nucleotide sequence of the ksgA gene of Escherichia coli: comparison of methyltransferases effecting dimethylation of adenosine in ribosomal RNA. Gene. 1985;38:65-72 pubmed
    The ksgA gene of Escherichia coli encodes a methyltransferase (MeT) that specifically dimethylates two adjacent adenosines near the 3' end of 16S RNA in the 30S particle. Its inactivation leads to kasugamycin (Ksg) resistance...
  3. Inoue K, Basu S, Inouye M. Dissection of 16S rRNA methyltransferase (KsgA) function in Escherichia coli. J Bacteriol. 2007;189:8510-8 pubmed
    A 16S rRNA methyltransferase, KsgA, identified originally in Escherichia coli is highly conserved in all living cells, from bacteria to humans...
  4. Cotney J, Shadel G. Evidence for an early gene duplication event in the evolution of the mitochondrial transcription factor B family and maintenance of rRNA methyltransferase activity in human mtTFB1 and mtTFB2. J Mol Evol. 2006;63:707-17 pubmed
    ..This class of transcription factors is homologous to the bacterial KsgA family of rRNA methyltransferases, which in Escherichia coli dimethylates adjacent adenine residues in a stem-loop ..
  5. LeVeque F, Blanchin Roland S, Fayat G, Plateau P, Blanquet S. Design and characterization of Escherichia coli mutants devoid of Ap4N-hydrolase activity. J Mol Biol. 1990;212:319-29 pubmed
    ..Variation deletions and insertions were also introduced in apaG and ksgA, two other cistrons of the ksgA apaGH operon...
  6. Connolly K, Culver G. Overexpression of RbfA in the absence of the KsgA checkpoint results in impaired translation initiation. Mol Microbiol. 2013;87:968-81 pubmed publisher
    b>KsgA, a universally conserved small ribosomal subunit (SSU) rRNA methyltransferase, has recently been shown to facilitate a checkpoint within the ribosome maturation pathway...
  7. Connolly K, Rife J, Culver G. Mechanistic insight into the ribosome biogenesis functions of the ancient protein KsgA. Mol Microbiol. 2008;70:1062-75 pubmed publisher
    ..A striking exception to this divergence is the universally conserved KsgA/Dim1p enzyme family, which modifies two adjacent adenosines in the terminal helix of small subunit ribosomal RNA (..
  8. Das G, Thotala D, Kapoor S, Karunanithi S, Thakur S, Singh N, et al. Role of 16S ribosomal RNA methylations in translation initiation in Escherichia coli. EMBO J. 2008;27:840-51 pubmed publisher
    ..Targeted mutations in the methyltransferase genes have revealed a connection between the rRNA modifications and the fundamental process of the initiator tRNA selection by the ribosome. ..
  9. Schuwirth B, Day J, Hau C, Janssen G, Dahlberg A, Cate J, et al. Structural analysis of kasugamycin inhibition of translation. Nat Struct Mol Biol. 2006;13:879-86 pubmed
    ..The present structural and biochemical results indicate that inhibition by Ksg and Ksg resistance are closely linked to the structure of the mRNA at the junction of the peptidyl-tRNA and exit-tRNA sites (P and E sites). ..

More Information


  1. Formenoy L, Cunningham P, Nurse K, Pleij C, Ofengand J. Methylation of the conserved A1518-A1519 in Escherichia coli 16S ribosomal RNA by the ksgA methyltransferase is influenced by methylations around the similarly conserved U1512.G1523 base pair in the 3' terminal hairpin. Biochimie. 1994;76:1123-8 pubmed
    ..with a complete mixture of 30S proteins to yield 30S ribosomal particles, which were tested for the ability of the ksgA methylase to form m6(2)A1518 and m6(2)A1519...
  2. Tormo A, Almiron M, Kolter R. surA, an Escherichia coli gene essential for survival in stationary phase. J Bacteriol. 1990;172:4339-47 pubmed
    ..Cells containing suppressing mutations then grew in the same culture to 10(8) cells per ml, taking over the population. The implications of these observations to our understanding of stationary-phase mutagenesis are discussed. ..
  3. Blanchin Roland S, Blanquet S, Schmitter J, Fayat G. The gene for Escherichia coli diadenosine tetraphosphatase is located immediately clockwise to folA and forms an operon with ksgA. Mol Gen Genet. 1986;205:515-22 pubmed
    ..Three other genes were identified in the flanking regions: ksgA, apaG and folA encoding, respectively, a 16 S rRNA methyltransferase, an unidentified protein of Mr 13,826 and ..
  4. Desai P, Culver G, Rife J. Site-directed mutants of 16S rRNA reveal important RNA domains for KsgA function and 30S subunit assembly. Biochemistry. 2011;50:854-63 pubmed publisher
    b>KsgA is an rRNA methyltransferase important to the process of small subunit biogenesis in bacteria. It is ubiquitously found in all life including archaea and eukarya, where the enzyme is referred to as Dim1...
  5. Zhang Akiyama Q, Morinaga H, Kikuchi M, Yonekura S, Sugiyama H, Yamamoto K, et al. KsgA, a 16S rRNA adenine methyltransferase, has a novel DNA glycosylase/AP lyase activity to prevent mutations in Escherichia coli. Nucleic Acids Res. 2009;37:2116-25 pubmed publisher
    ..The protein was subsequently purified from the E. coli mutM nth nei mutant and was identified as KsgA, a 16S rRNA adenine methyltransferase...
  6. Andrésson O, Davies J. Some properties of the ribosomal RNA methyltransferase encoded by ksgA and the polarity of ksgA transcription. Mol Gen Genet. 1980;179:217-22 pubmed
    The assay for the ksgA-encoded S-adenosylmethionine--6-N',N'-adenosyl (rRNA) dimethyltransferase has been improved; the gel-filtration molecular weight of partially purified enzyme under two different sets of conditions was found to be 55,..
  7. Helser T, Davies J, Dahlberg J. Mechanism of kasugamycin resistance in Escherichia coli. Nat New Biol. 1972;235:6-9 pubmed
  8. Roa B, Connolly D, Winkler M. Overlap between pdxA and ksgA in the complex pdxA-ksgA-apaG-apaH operon of Escherichia coli K-12. J Bacteriol. 1989;171:4767-77 pubmed
    ..The pdxA gene was cloned in the same 3.5-kilobase BamHI-EcoRI restriction fragment that contains ksgA, which encodes the 16S rRNA modification enzyme m6(2)A methyltransferase, and apaH, which encodes diadenosine ..
  9. Desai P, Rife J. The adenosine dimethyltransferase KsgA recognizes a specific conformational state of the 30S ribosomal subunit. Arch Biochem Biophys. 2006;449:57-63 pubmed
    The methyltransferase KsgA modifies two adjacent adenosines in 16S rRNA by adding two methyl groups to the N(6) position of each nucleotide...
  10. Poldermans B, Roza L, Van Knippenberg P. Studies on the function of two adjacent N6,N6-dimethyladenosines near the 3' end of 16 S ribosomal RNA of Escherichia coli. III. Purification and properties of the methylating enzyme and methylase-30 S interactions. J Biol Chem. 1979;254:9094-100 pubmed
  11. Seshadri A, Dubey B, Weber M, Varshney U. Impact of rRNA methylations on ribosome recycling and fidelity of initiation in Escherichia coli. Mol Microbiol. 2009;72:795-808 pubmed publisher
    ..We discuss these and earlier findings to propose that RRF plays a crucial role during all the steps of protein synthesis. ..
  12. Xu Z, O Farrell H, Rife J, Culver G. A conserved rRNA methyltransferase regulates ribosome biogenesis. Nat Struct Mol Biol. 2008;15:534-6 pubmed publisher
    In contrast to the diversity of most ribosomal RNA modification patterns and systems, the KsgA methyltransferase family seems to be nearly universally conserved along with the modifications it catalyzes...
  13. Campbell T, Brown E. Genetic interaction screens with ordered overexpression and deletion clone sets implicate the Escherichia coli GTPase YjeQ in late ribosome biogenesis. J Bacteriol. 2008;190:2537-45 pubmed publisher
    ..In addition, seven bona fide enhancers of slow growth were identified (delta tgt, delta ksgA, delta ssrA, delta rimM, delta rluD, delta trmE/mnmE, and delta trmU/mnmA) among 39 deletions (in genes associated ..
  14. van Gemen B, Twisk J, Van Knippenberg P. Autogenous regulation of the Escherichia coli ksgA gene at the level of translation. J Bacteriol. 1989;171:4002-8 pubmed
    Various plasmids that contain the Escherichia coli ksgA gene, which encodes a 16S rRNA adenosine dimethyltransferase (methylase), were constructed...
  15. O Farrell H, Scarsdale J, Rife J. Crystal structure of KsgA, a universally conserved rRNA adenine dimethyltransferase in Escherichia coli. J Mol Biol. 2004;339:337-53 pubmed
    The bacterial enzyme KsgA catalyzes the transfer of a total of four methyl groups from S-adenosyl-l-methionine (S-AdoMet) to two adjacent adenosine bases in 16S rRNA...
  16. Vila Sanjurjo A, Squires C, Dahlberg A. Isolation of kasugamycin resistant mutants in the 16 S ribosomal RNA of Escherichia coli. J Mol Biol. 1999;293:1-8 pubmed
    ..the absence of post-transcriptional modification at A1519 and the adjacent A1518 in strains lacking a functional KsgA methylase produces a kasugamycin resistance phenotype...
  17. Cunningham P, Weitzmann C, Nurse K, Masurel R, Van Knippenberg P, Ofengand J. Site-specific mutation of the conserved m6(2)A m6(2)A residues of E. coli 16S ribosomal RNA. Effects on ribosome function and activity of the ksgA methyltransferase. Biochim Biophys Acta. 1990;1050:18-26 pubmed
    ..The mutant ribosomes could also be methylated by the ksgA methyltransferase to 70-120% of the expected amount...
  18. Andrésson O, Davies J. Isolation and characterization of lambda transducing phages for the E. coli genes ksgA and pdxA. Mol Gen Genet. 1980;179:201-9 pubmed
    Lambda phages carrying the Escherichia coli genes ksgA and pdxA were isolated from secondary site lysogens in araB...
  19. O Farrell H, Musayev F, Scarsdale J, Rife J. Control of substrate specificity by a single active site residue of the KsgA methyltransferase. Biochemistry. 2012;51:466-74 pubmed publisher
    The KsgA methyltransferase is universally conserved and plays a key role in regulating ribosome biogenesis...
  20. Zimmermann R, Ikeya Y, Sparling P. Alteration of ribosomal protein S4 by mutation linked to kasugamycin-resistance in Escherichia coli. Proc Natl Acad Sci U S A. 1973;70:71-5 pubmed
    An alteration in the chromatographic mobility of 30S ribosomal protein S4 from two kasugamycin-resistant (ksgA) strains of E. coli was observed...
  21. O Farrell H, Musayev F, Scarsdale J, Wright H, Rife J. Crystallization and preliminary X-ray diffraction analysis of KsgA, a universally conserved RNA adenine dimethyltransferase in Escherichia coli. Acta Crystallogr D Biol Crystallogr. 2003;59:1490-2 pubmed
    The bacterial enzyme KsgA catalyzes the transfer of a total of four methyl groups from S-adenosylmethionine (SAM) to two adjacent adenosines in 16S rRNA...
  22. Pease A, Roa B, Luo W, Winkler M. Positive growth rate-dependent regulation of the pdxA, ksgA, and pdxB genes of Escherichia coli K-12. J Bacteriol. 2002;184:1359-69 pubmed
    ..pdxB genes, which mediate steps in the biosynthesis of the essential coenzyme pyridoxal 5"-phosphate, and the ksgA gene, which encodes an rRNA modification enzyme and is partly cotranscribed with pdxA, is subject to positive ..
  23. Dabbs E. The ribosomal components responsible for kasugamycin dependence, and its suppression, in a mutant of Escherichia coli. Mol Gen Genet. 1980;177:271-6 pubmed
    ..of a kasugamycin dependent mutant, MV17, was found to be the product of a kasugamycin resistance mutation in ksgA, together with a dependentizing mutation in rplW, the gene for large ribosomal subunit protein L23...
  24. Mangat C, Brown E. Ribosome biogenesis; the KsgA protein throws a methyl-mediated switch in ribosome assembly. Mol Microbiol. 2008;70:1051-3 pubmed
    ..The KsgA protein is a universally conserved methyltransferase that dimethylates both A1518 and A1519 of the 16S rRNA of the ..
  25. Sparling P. Kasugamycin resistance: 30S ribosomal mutation with an unusual location on the Escherichia coli chromosome. Science. 1970;167:56-8 pubmed
    ..Though all other known 30S ribosomal mutations are located in a cluster in the streptomycin region, kasugamycin resistance is located at a distance from this region, near the leucine region. ..
  26. Lu Q, Inouye M. The gene for 16S rRNA methyltransferase (ksgA) functions as a multicopy suppressor for a cold-sensitive mutant of era, an essential RAS-like GTP-binding protein in Escherichia coli. J Bacteriol. 1998;180:5243-6 pubmed
    ..coli genomic map, and the gene responsible for the suppression of Era(Cs) (E200K) was identified as the ksgA gene for 16S rRNA transmethylase, whose mutation causes a phenotype of resistance to kasugamycin, a translation ..
  27. Andrésson O, Davies J. Genetic organization and restriction enzyme cleavage map of the ksgA-pdxA region of the Escherichia coli chromosome. Mol Gen Genet. 1980;179:211-6 pubmed
    Small multicopy plasmids carrying the Escherichia coli genes ksgA and pdxA were constructed by ligation in vitro of an EcoRI restriction fragment from lambda ksg10 (Andrésson and Davies, 1980a) into the EcoRI sites of the ColE1 plasmids ..