Gene Symbol: ygcB
Description: Cascade complex anti-viral R-loop helicase-annealase Cas3
Alias: ECK2756, JW2731, cas3
Species: Escherichia coli str. K-12 substr. MG1655

Top Publications

  1. Brouns S, Jore M, Lundgren M, Westra E, Slijkhuis R, Snijders A, et al. Small CRISPR RNAs guide antiviral defense in prokaryotes. Science. 2008;321:960-4 pubmed publisher
    ..Assisted by the helicase Cas3, these mature CRISPR RNAs then serve as small guide RNAs that enable Cascade to interfere with virus proliferation...
  2. Westra E, van Erp P, Künne T, Wong S, Staals R, Seegers C, et al. CRISPR immunity relies on the consecutive binding and degradation of negatively supercoiled invader DNA by Cascade and Cas3. Mol Cell. 2012;46:595-605 pubmed publisher
    ..Both the Cascade ribonucleoprotein complex and the Cas3 nuclease/helicase are required for CRISPR interference in Escherichia coli, but it is unknown how natural target ..
  3. YOUNG R. Molecular biology. Secret weapon. Science. 2008;321:922-3 pubmed publisher
  4. Ivancic Bace I, Radovčić M, Bočkor L, Howard J, Bolt E. Cas3 stimulates runaway replication of a ColE1 plasmid in Escherichia coli and antagonises RNaseHI. RNA Biol. 2013;10:770-8 pubmed publisher
    b>Cas3 nuclease-helicase is part of CRISPR immunity systems in many bacteria and archaea. In type I CRISPR, Cas3 nuclease degrades invader DNA that has been base-paired to crRNA as an R-loop within a "Cascade" complex...
  5. Krone F, Westphal G, Schwenn J. Characterisation of the gene cysH and of its product phospho-adenylylsulphate reductase from Escherichia coli. Mol Gen Genet. 1991;225:314-9 pubmed
    ..Reduction of the enzyme by dithiols resulted in a shift of the apparent molecular weight from 44,000 to 62,000 without formation of an enzyme-thioredoxin complex. ..
  6. Howard J, Delmas S, Ivancic Bace I, Bolt E. Helicase dissociation and annealing of RNA-DNA hybrids by Escherichia coli Cas3 protein. Biochem J. 2011;439:85-95 pubmed publisher
    ..In the present paper, we report that purified E. coli Cas3 catalyses ATP-independent annealing of RNA with DNA forming R-loops, hybrids of RNA base-paired into duplex DNA...
  7. Redding S, Sternberg S, Marshall M, Gibb B, Bhat P, Guegler C, et al. Surveillance and Processing of Foreign DNA by the Escherichia coli CRISPR-Cas System. Cell. 2015;163:854-65 pubmed publisher
    ..complex for antiviral defense) is an RNA-guided surveillance complex that binds foreign DNA and recruits Cas3, a trans-acting nuclease helicase for target degradation...
  8. Majsec K, Bolt E, Ivančić Baće I. Cas3 is a limiting factor for CRISPR-Cas immunity in Escherichia coli cells lacking H-NS. BMC Microbiol. 2016;16:28 pubmed publisher
    ..This triggers degradation of invader DNA by Cas3 protein and in some circumstances stimulates capture of new invader DNA protospacers for incorporation into CRISPR ..
  9. Künne T, Kieper S, Bannenberg J, Vogel A, Miellet W, Klein M, et al. Cas3-Derived Target DNA Degradation Fragments Fuel Primed CRISPR Adaptation. Mol Cell. 2016;63:852-64 pubmed publisher
    ..We show that Cas3 couples CRISPR interference to adaptation by producing DNA breakdown products that fuel the spacer integration ..

More Information


  1. Jansen R, Embden J, Gaastra W, Schouls L. Identification of genes that are associated with DNA repeats in prokaryotes. Mol Microbiol. 2002;43:1565-75 pubmed
    ..The cas3 gene showed motifs characteristic for helicases of the superfamily 2, and the cas4 gene showed motifs of the RecB ..