Regulation of the Bacteriophage MugemOperon

Abstract The gem operon of bacteriophage Mu, responsible for the complex phenomenon of phage conversion, is included in the so called “semiessential early” region of phage DNA. Unlike the other early genes of the phage which are transcribed from the p e promoter, expression of the gem operon is driven by its own promoter, which escapes the control of the repressor. In fact, the transcript corresponding to gem was detected in immune lysogens by using a combined reverse transcription and a subsequent amplification of the resulting cDNA. The transcription initiation site from p gem was determined by primer extension mapping experiments and localized at 8217 bp from the left end of phage DNA. Two elements which could perform the negative control of gem were also identified. The first is a phage product, GemB, which presumably interferes with gem expression at a posttranscriptional level, whereas the second is a structural element, an inverted repeat immediately downstream of p gem , which acts as a terminator for the transcripts starting from p e . These transcripts could regulate gem expression by interfering with the initiation of transcription from p gem .

[1]  G. Di Lallo,et al.  A spontaneous Escherichia coli K12 mutant which inhibits the excision-reintegration process of Mu gem2ts. , 1997, FEMS Microbiology Letters.

[2]  R. La Valle,et al.  Bacteriophage Mu gem2ts, which induces synchronous cell division in the infected host, is mutated in the gem operon promoter. , 1996, Research in microbiology.

[3]  P. Saris,et al.  Characterization of prokaryotic mRNAs by RT-PCR. , 1995, BioTechniques.

[4]  R. D'ari,et al.  A novel illegitimate recombination event: precise excision and reintegration with the Mu gem mutant prophage , 1994, Molecular microbiology.

[5]  L. Paolozzi,et al.  A case of lysogenic conversion: modification of cell phenotype by constitutive expression of the Mu gem operon. , 1992, Research in microbiology.

[6]  R M Atlas,et al.  Detection of bacterial mRNA using polymerase chain reaction. , 1991, BioTechniques.

[7]  V. Orlando,et al.  Synchronous division induced in Escherichia coli K12 by phage Mu: analysis of DNA topology and gene expression during the cell cycle. , 1991, Research in microbiology.

[8]  G. Di Lallo,et al.  The bacteriophage Mu gem gene: a positive regulator of the C operon required for normal levels of late transcription. , 1990, Virology.

[9]  K. Mathee,et al.  Identification of a positive regulator of the Mu middle operon , 1990, Journal of bacteriology.

[10]  I. Ruberti,et al.  Mu gem3 as a tool to investigate the influence of chromosome supercoiling on gene expression in Escherichia coli K12 , 1990 .

[11]  M. Becker‐André,et al.  Absolute mRNA quantification using the polymerase chain reaction (PCR). A novel approach by a PCR aided transcript titration assay (PATTY). , 1989, Nucleic acids research.

[12]  S. Wirsel,et al.  Three α‐amylase genes of Aspergillus oryzae exhibit identical intron‐exon organization , 1989 .

[13]  E. Craig,et al.  Primer extension analysis of RNA. , 1989, Methods in enzymology.

[14]  S. Cohen,et al.  In vitro gene fusions that join an enzymatically active beta-galactosidase segment to amino-terminal fragments of exogenous proteins: Escherichia coli plasmid vectors for the detection and cloning of translational initiation signals , 1980, Journal of bacteriology.

[15]  L. Paolozzi,et al.  Restoration of ligase activity in E. coli K12 lig ts7 strain by bacteriophage Mu and cloning of a DNA fragment harbouring the Mu 'lig' gene. , 1980, Nucleic Acids Research.

[16]  J. Lis.  Fractionation of DNA fragments by polyethylene glycol induced precipitation. , 1980, Methods in enzymology.

[17]  M. Giphart-Gassler,et al.  Is Integration Essential for Mu Development , 1978 .

[18]  P. Hofschneider,et al.  Integration and Excision of DNA Molecules , 1978, Colloquium der Gesellschaft für Biologische Chemie in Mosbach Baden.

[19]  Jeffrey H. Miller.  Experiments in molecular genetics , 1972 .