The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
MeSH Review

F Factor

Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of F Factor

  • The most significant feature in this regard may be the lack of a region of dyad symmetry within the presumptive promoter of the F plasmid ssf gene as is found in the region of the presumptive E. coli ssb promoter [1].
  • A purified EcoRI restriction endonuclease fragment that determines resistance to kanamycin and is incapable of self-replication was used to select autonomously replicating fragments from an EcoRI digest of a Salmonella typhimurium F' plasmid containing the chromosomal region believed to include the S. typhimurium origin of DNA replication [2].
  • The single-stranded DNA-binding proteins from bacteriophage T4, F plasmid, Escherichia coli, and calf thymus can all be covalently cross-linked in vitro to thymine oligonucleotides by irradiating the respective protein-oligonucleotide complexes with ultraviolet light [3].
  • Repression of the virulence of Yersinia pestis by an F' plasmid [4].
  • Thus, as the influenza C glycoprotein is the only myxovirus glycoprotein with three different activities, we propose the designation HEF in order to describe its function as a haemagglutinin (H), an esterase (E) and a fusion factor (F) [5].

High impact information on F Factor

  • Derived from the leading region of F plasmid, single-stranded Frpo sequence directs RNA polymerase to initiate transcription at a specific site within Frpo, and this specific transcription is highly stimulated by SSB [6].
  • This strain carries a revertible mutant lac allele on an F plasmid and accumulates Lac+ (lactose utilizing) revertants, but not unselected mutants, when placed on selective medium [7].
  • The anticoagulant effect of short heparin chains, including the minimal AT-specific pentasaccharide, is mediated exclusively through the allosteric activation of AT towards efficient inhibition of coagulation factors (f) IXa and Xa [8].
  • The protein FinO represses F-plasmid conjugative transfer by facilitating interactions between the mRNA of the major F-plasmid transcriptional activator, TraJ, and an antisense RNA, FinP [9].
  • It is plausible that the near polar localization of SopB may serve the function of keeping a segregated pair of F plasmids apart while the cell septum is being formed [10].

Chemical compound and disease context of F Factor

  • Hfr strains that carry the F factor adjacent to argF (one of two duplicate genes that code for ornithine transcarbamylase in E. coli K12) yield more Cut mutants than do F+ or F- strains, or Hfr strains in which the F factor is not adjacent to argF [11].
  • Several F' plasmids encoding resistance to tetracycline have been derived from a trg::Tn10 Hfr B7 strain of Escherichia coli K-12 [12].
  • The aberrantly regulated dihydrofolate reductase gene mediating trimethoprim resistance could be transduced into E. coli K-12 or moved by recombination into an F' factor and then transferred into trans position in relation to the corresponding chromosomal gene [13].
  • Sixty-two E. coli mutants, selected as being deficient as recipients in F factor conjugation, are altered either in the amount or function of the outer membrane OmpA protein or in lipopolysaccharide structure [14].

Biological context of F Factor

  • The drug-resistance plasmid, NR1, is a 37-micron circular DNA molecule that contains two components: the resistance transfer factor (29 micron) carrying the transfer genes and the genes for tetracycline resistance, and the r-determinant (8 micron) carrying the genes for resistance to several other antibiotics including chloramphenicol (Cm) [15].
  • In Escherichia coli K-12 strains that carry the mutation ssb-1 in the gene for single-stranded DNA binding protein, the presence of the F sex factor partially reverses the temperature-sensitive growth phenotype caused by the mutation [16].
  • Dispensable replicons such as F plasmid [95 kilobases (kb)] or its mini-derivatives such as mini-F (9.3 kb) or lambda mini-F efficiently induced cellular SOS genes such as sfiA (sulA) when they were damaged by UV irradiation and then introduced into a recipient bacterium [17].
  • We have determined the sequence of the gene encoding a single-stranded DNA (ss DNA) binding protein (SSB) from the Escherichia coli F sex factor and the amino acid sequence of the protein it encodes [1].
  • Recently, molecular genetic studies have suggested that DNA helicase I, which is known to be encoded on the F plasmid, may be involved in this nicking reaction (Traxler, B. A., and Minkley, E. G., Jr. (1988) J. Mol. Biol. 204, 205-209) [18].

Anatomical context of F Factor

  • The different functional complexes of ribosomes with elongation factor F (EF-G) were studied by digestion experiments with trypsin [19].
  • Due to the reported lack of factor (F) X in semen, it has been suggested that TF may not have a role in seminal coagulum formation [20].
  • Monocytes synthesize factor (F) XIII, implying that FXIII (a and s) in synovial tissue might help to differentiate between RA and OA [21].
  • Thus, correlations between the peroxidation level, superoxide dismutase (SOD) activity, antioxidant factor (F), and indexes of resistance of erythrocytes for hemolysis (TR) were found [22].

Associations of F Factor with chemical compounds

  • Steroid/nuclear hormone receptors are ligand-regulated transcription f factors that play key roles in cell regulation, differentiation, and oncogenesis [23].
  • The protein cofactor, factor (F) VIIIa, is required for the efficient conversion of the substrate FX to FXa by the serine protease FIXa [24].
  • Transfer of all three plasmids was affected differently by mutations in the rfa (LPS) locus of the recipient cell, the F plasmid being most sensitive to mutations that affected rfaP gene expression which is responsible for the addition of pyrophosphorylethanolamine (PPEA) to heptose I of the inner core of the LPS [25].
  • ColB2 transfer was more strongly affected by mutations in the heptose II-heptose III region of the LPS (rfaF) whereas R100-1 was not strongly affected by any of the rfa mutations tested. ompA but not rfa mutations further decreased the mating efficiency of an F plasmid carrying a mutation in the mating-pair stabilization protein TraN [25].
  • Genetic factors affecting recovery of nonpoint mutations in the region of a gene coding for ornithine transcarbamylase: involvement of both the F factor in its chromosomal state and the recA gene [11].

Gene context of F Factor

  • When a chimeric construct between pBR322 and pSC101 was introduced into a polA rnh double mutant, the replication of the plasmid via the pBR322 replicon was inhibited if the plasmid also carried an rnh+ gene or if the host harbored an F' plasmid carrying an rnh+ gene [26].
  • Using a traD overexpression plasmid, we purified the F sex factor TraD protein in milligram quantities [27].
  • Protein Z-dependent protease inhibitor (ZPI) is a serpin inhibitor of coagulation factor (F) Xa dependent on protein Z, Ca2+, and phospholipids [28].
  • srnB is an F-plasmid encoded gene, otherwise silent, whose expression is induced by added rifampicin, leading to the release of cellular Mg2+ and degradation of stable RNA [29].
  • The F sex factor also carries a psiB gene homologous to that of R6-5 [30].

Analytical, diagnostic and therapeutic context of F Factor


  1. F sex factor encodes a single-stranded DNA binding protein (SSB) with extensive sequence homology to Escherichia coli SSB. Chase, J.W., Merrill, B.M., Williams, K.R. Proc. Natl. Acad. Sci. U.S.A. (1983) [Pubmed]
  2. Isolation and mapping of plasmids containing the Salmonella typhimurium origin of DNA replication. Zyskind, J.W., Deen, L.T., Smith, D.W. Proc. Natl. Acad. Sci. U.S.A. (1979) [Pubmed]
  3. Photochemical cross-linking of the Escherichia coli single-stranded DNA-binding protein to oligodeoxynucleotides. Identification of phenylalanine 60 as the site of cross-linking. Merrill, B.M., Williams, K.R., Chase, J.W., Konigsberg, W.H. J. Biol. Chem. (1984) [Pubmed]
  4. Repression of the virulence of Yersinia pestis by an F' plasmid. Zsigray, R.M., Lawton, W.D., Surgalla, M.J. Infect. Immun. (1983) [Pubmed]
  5. The glycoprotein of influenza C virus is the haemagglutinin, esterase and fusion factor. Herrler, G., Dürkop, I., Becht, H., Klenk, H.D. J. Gen. Virol. (1988) [Pubmed]
  6. Frpo: a novel single-stranded DNA promoter for transcription and for primer RNA synthesis of DNA replication. Masai, H., Arai, K. Cell (1997) [Pubmed]
  7. Evidence that F plasmid transfer replication underlies apparent adaptive mutation. Galitski, T., Roth, J.R. Science (1995) [Pubmed]
  8. Antithrombin-S195A factor Xa-heparin structure reveals the allosteric mechanism of antithrombin activation. Johnson, D.J., Li, W., Adams, T.E., Huntington, J.A. EMBO J. (2006) [Pubmed]
  9. FinO is an RNA chaperone that facilitates sense-antisense RNA interactions. Arthur, D.C., Ghetu, A.F., Gubbins, M.J., Edwards, R.A., Frost, L.S., Glover, J.N. EMBO J. (2003) [Pubmed]
  10. Localization of F plasmid SopB protein to positions near the poles of Escherichia coli cells. Kim, S.K., Wang, J.C. Proc. Natl. Acad. Sci. U.S.A. (1998) [Pubmed]
  11. Genetic factors affecting recovery of nonpoint mutations in the region of a gene coding for ornithine transcarbamylase: involvement of both the F factor in its chromosomal state and the recA gene. Jessop, A.P., Glansdorff, N. Genetics (1980) [Pubmed]
  12. Origin of Escherichia coli K-12 Hfr B7. Virolle, M.J., Gélugne, J.P., Béjar, S., Bouché, J.P. J. Bacteriol. (1983) [Pubmed]
  13. New observations regarding evolution of trimethoprim resistance. Tennhammar-Ekman, B., Sundström, L., Sköld, O. J. Antimicrob. Chemother. (1986) [Pubmed]
  14. Conjugation-deficient mutants of Escherichia coli distinguish classes of functions of the outer membrane OmpA protein. Manoil, C., Rosenbusch, J.P. Mol. Gen. Genet. (1982) [Pubmed]
  15. Selective amplification of genes on the R plasmid, NR1, in Proteus mirabilis: an example of the induction of selective gene amplification. Perlman, D., Stickgold, R. Proc. Natl. Acad. Sci. U.S.A. (1977) [Pubmed]
  16. F sex factor of Escherichia coli K-12 codes for a single-stranded DNA binding protein. Kolodkin, A.L., Capage, M.A., Golub, E.I., Low, K.B. Proc. Natl. Acad. Sci. U.S.A. (1983) [Pubmed]
  17. Mini-F plasmid-induced SOS signal in Escherichia coli is RecBC dependent. Bailone, A., Sommer, S., Devoret, R. Proc. Natl. Acad. Sci. U.S.A. (1985) [Pubmed]
  18. Escherichia coli DNA helicase I catalyzes a site- and strand-specific nicking reaction at the F plasmid oriT. Matson, S.W., Morton, B.S. J. Biol. Chem. (1991) [Pubmed]
  19. The L7/L12 proteins change their conformation upon interaction of EF-G with ribosomes. Gudkov, A.T., Gongadze, G.M. FEBS Lett. (1984) [Pubmed]
  20. Seminal tissue factor revisited. Lwaleed, B., Jackson, C., Greenfield, R., Stewart, A., Delves, G., Birch, B., Cooper, A. Int. J. Androl. (2006) [Pubmed]
  21. Immunohistochemical detection of factor XIIIa and factor XIIIs in synovial membranes of patients with rheumatoid arthritis or osteoarthritis. Plenz, A., Fritz, P., König, G., Laschner, W., Saal, J.G. Rheumatol. Int. (1996) [Pubmed]
  22. Influence of cis-[Re2GABA2Cl4]Cl2 on the antioxidant defense system parameters of normal human blood. Pirozhkova-Patalah, I.V., Shtemenko, N.I. Biochemistry Mosc. (2001) [Pubmed]
  23. Selective effects of ligands on vitamin D3 receptor- and retinoid X receptor-mediated gene activation in vivo. Lemon, B.D., Freedman, L.P. Mol. Cell. Biol. (1996) [Pubmed]
  24. Localization of a factor X interactive site in the A1 subunit of factor VIIIa. Lapan, K.A., Fay, P.J. J. Biol. Chem. (1997) [Pubmed]
  25. The role of the pilus in recipient cell recognition during bacterial conjugation mediated by F-like plasmids. Anthony, K.G., Sherburne, C., Sherburne, R., Frost, L.S. Mol. Microbiol. (1994) [Pubmed]
  26. Absence of RNase H allows replication of pBR322 in Escherichia coli mutants lacking DNA polymerase I. Kogoma, T. Proc. Natl. Acad. Sci. U.S.A. (1984) [Pubmed]
  27. Purification and properties of the F sex factor TraD protein, an inner membrane conjugal transfer protein. Panicker, M.M., Minkley, E.G. J. Biol. Chem. (1992) [Pubmed]
  28. Down-regulation of factor IXa in the factor Xase complex by protein Z-dependent protease inhibitor. Heeb, M.J., Cabral, K.M., Ruan, L. J. Biol. Chem. (2005) [Pubmed]
  29. Transcriptional regulation of F plasmid gene srnB: rifampicin-promoted in vitro readthrough of a terminator in the leader region. Akimoto, S., Sakikawa, T., Ono, K., Ono, T., Ohnishi, Y. Mol. Microbiol. (1989) [Pubmed]
  30. Identification of psiB genes of plasmids F and R6-5. Molecular basis for psiB enhanced expression in plasmid R6-5. Dutreix, M., Bäckman, A., Célérier, J., Bagdasarian, M.M., Sommer, S., Bailone, A., Devoret, R., Bagdasarian, M. Nucleic Acids Res. (1988) [Pubmed]
  31. Escherichia coli DNA helicase I catalyzes a sequence-specific cleavage/ligation reaction at the F plasmid origin of transfer. Sherman, J.A., Matson, S.W. J. Biol. Chem. (1994) [Pubmed]
  32. Purification, circular dichroism analysis, crystallization and preliminary X-ray diffraction analysis of the F plasmid CcdB killer protein. Steyaert, J., Van Melderen, L., Bernard, P., Thi, M.H., Loris, R., Wyns, L., Couturier, M. J. Mol. Biol. (1993) [Pubmed]
  33. Partner switching mechanisms in inactivation and rejuvenation of Escherichia coli DNA gyrase by F plasmid proteins LetD (CcdB) and LetA (CcdA). Maki, S., Takiguchi, S., Horiuchi, T., Sekimizu, K., Miki, T. J. Mol. Biol. (1996) [Pubmed]
  34. Requirement for the polymerization and 5'-->3' exonuclease activities of DNA polymerase I in initiation of DNA replication at oriK sites in the absence of RecA in Escherichia coli rnhA mutants. Cao, Y., Kogoma, T. J. Bacteriol. (1993) [Pubmed]
  35. Immunobiology of inhibitor development in hemophilia A. Fijnvandraat, K., Bril, W.S., Voorberg, J. Semin. Thromb. Hemost. (2003) [Pubmed]
WikiGenes - Universities