• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Mar 1988; 85(6): 1806–1810.
PMCID: PMC279868

RecA protein-dependent cleavage of UmuD protein and SOS mutagenesis.


Induction of the Escherichia coli SOS system increases the ability of the cell to perform DNA repair and mutagenesis. Products of the recA and umuD,C genes are required for mutagenesis induced by radiation and many chemicals. Transcription of the SOS genes including recA and umuD,C is repressed by a repressor, LexA protein, and is derepressed by the proteolytic cleavage of LexA facilitated by RecA protein that had been activated by inducing signals produced in the cell by agents that damage DNA. An activated form of RecA protein, RecA, seems to have roles in SOS mutagenesis other than its known role as an antirepressor. Derepression of the genes involved in SOS mutagenesis such as recA and umuD,C in defective chromosomal lexA(Def) mutants does not increase the ability of the cell to perform mutagenesis. Activation of RecA protein is essential to this ability. RecA facilitates the proteolytic cleavage of several repressors such as lambda, P22, and 434 phage repressors and LexA, and UmuD protein contains a sequence homologous to the regions surrounding the cleavage sites of these repressors; therefore, we examined the possibility that UmuD protein is cleaved by RecA. We found evidence that the intact UmuD protein was cleaved after mutagenic treatment and that the cleavage was dependent on RecA. The results suggested that UmuD protein may be proteolytically processed by RecA, and that processed UmuD may be the active form of the protein participating in mutagenesis.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.3M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Witkin EM. Ultraviolet mutagenesis and inducible DNA repair in Escherichia coli. Bacteriol Rev. 1976 Dec;40(4):869–907. [PMC free article] [PubMed]
  • Little JW, Mount DW. The SOS regulatory system of Escherichia coli. Cell. 1982 May;29(1):11–22. [PubMed]
  • Walker GC. Mutagenesis and inducible responses to deoxyribonucleic acid damage in Escherichia coli. Microbiol Rev. 1984 Mar;48(1):60–93. [PMC free article] [PubMed]
  • Kato T, Shinoura Y. Isolation and characterization of mutants of Escherichia coli deficient in induction of mutations by ultraviolet light. Mol Gen Genet. 1977 Nov 14;156(2):121–131. [PubMed]
  • Steinborn G. Uvm mutants of Escherichia coli K12 deficient in UV mutagenesis. I. Isolation of uvm mutants and their phenotypical characterization in DNA repair and mutagenesis. Mol Gen Genet. 1978 Sep 20;165(1):87–93. [PubMed]
  • Elledge SJ, Walker GC. Proteins required for ultraviolet light and chemical mutagenesis. Identification of the products of the umuC locus of Escherichia coli. J Mol Biol. 1983 Feb 25;164(2):175–192. [PubMed]
  • Shinagawa H, Kato T, Ise T, Makino K, Nakata A. Cloning and characterization of the umu operon responsible for inducible mutagenesis in Escherichia coli. Gene. 1983 Aug;23(2):167–174. [PubMed]
  • Little JW, Mount DW, Yanisch-Perron CR. Purified lexA protein is a repressor of the recA and lexA genes. Proc Natl Acad Sci U S A. 1981 Jul;78(7):4199–4203. [PMC free article] [PubMed]
  • Kitagawa Y, Akaboshi E, Shinagawa H, Horii T, Ogawa H, Kato T. Structural analysis of the umu operon required for inducible mutagenesis in Escherichia coli. Proc Natl Acad Sci U S A. 1985 Jul;82(13):4336–4340. [PMC free article] [PubMed]
  • Horii T, Ogawa T, Nakatani T, Hase T, Matsubara H, Ogawa H. Regulation of SOS functions: purification of E. coli LexA protein and determination of its specific site cleaved by the RecA protein. Cell. 1981 Dec;27(3 Pt 2):515–522. [PubMed]
  • Blanco M, Herrera G, Collado P, Rebollo JE, Botella LM. Influence of RecA protein on induced mutagenesis. Biochimie. 1982 Aug-Sep;64(8-9):633–636. [PubMed]
  • Ennis DG, Fisher B, Edmiston S, Mount DW. Dual role for Escherichia coli RecA protein in SOS mutagenesis. Proc Natl Acad Sci U S A. 1985 May;82(10):3325–3329. [PMC free article] [PubMed]
  • Witkin EM, Kogoma T. Involvement of the activated form of RecA protein in SOS mutagenesis and stable DNA replication in Escherichia coli. Proc Natl Acad Sci U S A. 1984 Dec;81(23):7539–7543. [PMC free article] [PubMed]
  • Perry KL, Elledge SJ, Mitchell BB, Marsh L, Walker GC. umuDC and mucAB operons whose products are required for UV light- and chemical-induced mutagenesis: UmuD, MucA, and LexA proteins share homology. Proc Natl Acad Sci U S A. 1985 Jul;82(13):4331–4335. [PMC free article] [PubMed]
  • Bachmann BJ. Pedigrees of some mutant strains of Escherichia coli K-12. Bacteriol Rev. 1972 Dec;36(4):525–557. [PMC free article] [PubMed]
  • George J, Castellazzi M, Buttin G. Prophage induction and cell division in E. coli. III. Mutations sfiA and sfiB restore division in tif and lon strains and permit the expression of mutator properties of tif. Mol Gen Genet. 1975 Oct 22;140(4):309–332. [PubMed]
  • Marsh L, Walker GC. Cold sensitivity induced by overproduction of UmuDC in Escherichia coli. J Bacteriol. 1985 Apr;162(1):155–161. [PMC free article] [PubMed]
  • Wertman KF, Mount DW. Nucleotide sequence binding specificity of the LexA repressor of Escherichia coli K-12. J Bacteriol. 1985 Jul;163(1):376–384. [PMC free article] [PubMed]
  • Bolivar F, Rodriguez RL, Greene PJ, Betlach MC, Heyneker HL, Boyer HW, Crosa JH, Falkow S. Construction and characterization of new cloning vehicles. II. A multipurpose cloning system. Gene. 1977;2(2):95–113. [PubMed]
  • Rüther U, Müller-Hill B. Easy identification of cDNA clones. EMBO J. 1983;2(10):1791–1794. [PMC free article] [PubMed]
  • Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. [PubMed]
  • Ullmann A. One-step purification of hybrid proteins which have beta-galactosidase activity. Gene. 1984 Jul-Aug;29(1-2):27–31. [PubMed]
  • OUCHTERLONY O. Antigen-antibody reactions in gels. IV. Types of reactions in coordinated systems of diffusion. Acta Pathol Microbiol Scand. 1953;32(2):230–240. [PubMed]
  • Towbin H, Staehelin T, Gordon J. Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350–4354. [PMC free article] [PubMed]
  • Shinagawa H, Mizuuchi K, Emmerson PT. Induction of prophage lambda by gamma-rays, mitomycin C and tif; repressor cleavage studied by immunoprecipitation. Mol Gen Genet. 1977 Sep 21;155(1):87–91. [PubMed]
  • Witkin EM, McCall JO, Volkert MR, Wermundsen IE. Constitutive expression of SOS functions and modulation of mutagenesis resulting from resolution of genetic instability at or near the recA locus of Escherichia coli. Mol Gen Genet. 1982;185(1):43–50. [PubMed]
  • Burckhardt SE, Woodgate R, Scheuermann RH, Echols H. UmuD mutagenesis protein of Escherichia coli: overproduction, purification, and cleavage by RecA. Proc Natl Acad Sci U S A. 1988 Mar;85(6):1811–1815. [PMC free article] [PubMed]
  • Little JW, Edmiston SH, Pacelli LZ, Mount DW. Cleavage of the Escherichia coli lexA protein by the recA protease. Proc Natl Acad Sci U S A. 1980 Jun;77(6):3225–3229. [PMC free article] [PubMed]
  • Little JW. Autodigestion of lexA and phage lambda repressors. Proc Natl Acad Sci U S A. 1984 Mar;81(5):1375–1379. [PMC free article] [PubMed]
  • Nohmi T, Battista JR, Dodson LA, Walker GC. RecA-mediated cleavage activates UmuD for mutagenesis: mechanistic relationship between transcriptional derepression and posttranslational activation. Proc Natl Acad Sci U S A. 1988 Mar;85(6):1816–1820. [PMC free article] [PubMed]
  • Blanco M, Herrera G, Aleixandre V. Different efficiency of UmuDC and MucAB proteins in UV light induced mutagenesis in Escherichia coli. Mol Gen Genet. 1986 Nov;205(2):234–239. [PubMed]
  • Bridges BA, Woodgate R. Mutagenic repair in Escherichia coli: products of the recA gene and of the umuD and umuC genes act at different steps in UV-induced mutagenesis. Proc Natl Acad Sci U S A. 1985 Jun;82(12):4193–4197. [PMC free article] [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...