Gene Symbol: hflX
Description: GTPase, stimulated by 50S subunit binding; Mn(2+) homeostasis regulator
Alias: ECK4169, JW4131, hflA, hslX
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Dutta D, Bandyopadhyay K, Datta A, Sardesai A, Parrack P. Properties of HflX, an enigmatic protein from Escherichia coli. J Bacteriol. 2009;191:2307-14 pubmed publisher
    The Escherichia coli gene hflX was first identified as part of the hflA operon, mutations in which led to an increased frequency of lysogenization upon infection of the bacterium by the temperate coliphage lambda...
  2. Twiss E, Coros A, Tavakoli N, Derbyshire K. Transposition is modulated by a diverse set of host factors in Escherichia coli and is stimulated by nutritional stress. Mol Microbiol. 2005;57:1593-607 pubmed
    ..In summary, this work identifies a collection of proteins that allow the host to modulate transposition in response to cell stress. ..
  3. Banuett F, Herskowitz I. Identification of polypeptides encoded by an Escherichia coli locus (hflA) that governs the lysis-lysogeny decision of bacteriophage lambda. J Bacteriol. 1987;169:4076-85 pubmed
    ..Last, we describe evidence that hflA contains an additional gene, hflX, encoding a 50,000-dalton polypeptide.
  4. Jain N, Dhimole N, Khan A, De D, Tomar S, Sajish M, et al. E. coli HflX interacts with 50S ribosomal subunits in presence of nucleotides. Biochem Biophys Res Commun. 2009;379:201-5 pubmed publisher
    b>HflX is a GTP binding protein of unknown function. Based on the presence of the hflX gene in hflA operon, HflX was believed to be involved in the lytic-lysogenic decision during phage infection in Escherichia coli. We find that E...
  5. Cronan J, Silbert D, Wulff D. Mapping of the fabA locus for unsaturated fatty acid biosynthesis in Escherichia coli. J Bacteriol. 1972;112:206-11 pubmed
    ..5 of the linkage map of E. coli. The locus is cotransduced with pyrD and aroA but not with pyrC, purB, or pdxC. The clockwise order of markers in the region is pdxC, aroA, cmlB, pyrD, fabA, pyrC. ..
  6. Kajitani M, Ishihama A. Identification and sequence determination of the host factor gene for bacteriophage Q beta. Nucleic Acids Res. 1991;19:1063-6 pubmed
    ..Sequence determination of the cloned hfq gene indicated that HF-I is a small protein of Mr 11,166 consisting of 102 amino acid residues. ..
  7. Coatham M, Brandon H, Fischer J, Schümmer T, Wieden H. The conserved GTPase HflX is a ribosome splitting factor that binds to the E-site of the bacterial ribosome. Nucleic Acids Res. 2016;44:1952-61 pubmed publisher
    ..kinetics techniques we reveal for the first time that the universally conserved translational GTPase (trGTPase) HflX binds to the E-site of the 70S ribosome and that its GTPase activity is modulated by peptidyl transferase centre (..
  8. Ghosh A, Dutta D, Bandyopadhyay K, Parrack P. Characterization of the autophosphorylation property of HflX, a ribosome-binding GTPase from Escherichia coli. FEBS Open Bio. 2016;6:651-9 pubmed publisher
    Escherichia coli HflX belongs to the widely distributed but poorly characterized HflX family of translation factor-related GTPases that is conserved from bacteria to humans...
  9. Zhang Y, Mandava C, Cao W, Li X, Zhang D, Li N, et al. HflX is a ribosome-splitting factor rescuing stalled ribosomes under stress conditions. Nat Struct Mol Biol. 2015;22:906-13 pubmed publisher
    ..Here, we used fast kinetics and cryo-EM to characterize Escherichia coli HflX, a GTPase with unknown function...

More Information


  1. Brown E. Conserved P-loop GTPases of unknown function in bacteria: an emerging and vital ensemble in bacterial physiology. Biochem Cell Biol. 2005;83:738-46 pubmed
    ..of a group of 8 conserved, poorly characterized genes encoding P-loop GTPases, era, obg, trmE, yjeQ, engA, yihA, hflX, ychF, and a related ATPase, yjeE, are reviewed in considerable detail...
  2. Kitagawa R, Mitsuki H, Okazaki T, Ogawa T. A novel DnaA protein-binding site at 94.7 min on the Escherichia coli chromosome. Mol Microbiol. 1996;19:1137-47 pubmed
    ..A role for the DnaA-binding site in controlling DnaA-protein concentration in the cell cycle is discussed. ..
  3. Tsui H, Winkler M. Transcriptional patterns of the mutL-miaA superoperon of Escherichia coli K-12 suggest a model for posttranscriptional regulation. Biochimie. 1994;76:1168-77 pubmed
    The complex amiB-mutL-miaA-hfq-hflX-hflK-hflC superoperon of E coli contains important genes for several fundamental cellular processes, including cell-wall hydrolysis (amiB), DNA repair (mutL), tRNA modification (miaA) and proteolysis (..
  4. Gautsch J, Wulff D. Fine structure mapping, complementation, and physiology of Escherichia coli hfl mutants. Genetics. 1974;77:435-48 pubmed
    ..It is further argued that the function of the lambdacIII gene product is to negate the antagonistic effect of this hfl(+) protein. ..
  5. Tsui H, Feng G, Winkler M. Transcription of the mutL repair, miaA tRNA modification, hfq pleiotropic regulator, and hflA region protease genes of Escherichia coli K-12 from clustered Esigma32-specific promoters during heat shock. J Bacteriol. 1996;178:5719-31 pubmed
    The amiB-mutL-miaA-hfq-hflX-hflK-hflC superoperon of Escherichia coli contains genes that are important for diverse cellular functions, including DNA mismatch repair (mutL), tRNA modification (miaA), pleiotropic regulation (hfq), and ..
  6. Chuang S, Blattner F. Characterization of twenty-six new heat shock genes of Escherichia coli. J Bacteriol. 1993;175:5242-52 pubmed
    ..Possible assignments of some of the hsl genes to known proteins are discussed. ..
  7. Noble J, Innis M, Koonin E, Rudd K, Banuett F, Herskowitz I. The Escherichia coli hflA locus encodes a putative GTP-binding protein and two membrane proteins, one of which contains a protease-like domain. Proc Natl Acad Sci U S A. 1993;90:10866-70 pubmed
    The hflA (high frequency of lysogenization) locus of Escherichia coli governs the lysis-lysogeny decision of bacteriophage lambda by controlling stability of the phage cII protein...
  8. Tsui H, Leung H, Winkler M. Characterization of broadly pleiotropic phenotypes caused by an hfq insertion mutation in Escherichia coli K-12. Mol Microbiol. 1994;13:35-49 pubmed
    ..different from the parent, although transcript mapping demonstrated that the insertion was completely polar on hflX expression...
  9. Shields M, Fischer J, Wieden H. Toward understanding the function of the universally conserved GTPase HflX from Escherichia coli: a kinetic approach. Biochemistry. 2009;48:10793-802 pubmed publisher
    ..The universally conserved GTPase HflX has previously been shown to associate with the 50S ribosomal subunit, as well as to bind and hydrolyze both GTP ..
  10. Hoyt M, Knight D, Das A, Miller H, Echols H. Control of phage lambda development by stability and synthesis of cII protein: role of the viral cIII and host hflA, himA and himD genes. Cell. 1982;31:565-73 pubmed
    ..We have found that the stability of cII is controlled by the host hflA and viral cIII genes; hflA protein facilitates degradation of cII, whereas cIII protects cII...