Two states of expression of genes cl, rex, and N in lambda

Spiegelman, Willard G.

doi:10.1016/0042-6822(71)90220-0

Cited by 37 publications

(11 citation statements)

References 21 publications

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“…The rexAB genes of , like the stk gene of 933W, are located just downstream of the cI gene. Both rex genes are expressed by the repressed prophage by transcription initiating at p RM (52,57), while rexB is also expressed from a promoter in rexA (Fig. 1A) (32, 33).…”

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confidence: 99%

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Characterization of a Eukaryotic-Like Tyrosine Protein Kinase Expressed by the Shiga Toxin-Encoding Bacteriophage 933W

Tyler

Friedman

2004

J Bacteriol

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The Shiga toxin (Stx)-encoding bacteriophage 933W contains an open reading frame, stk, with amino acid sequence similarity to the catalytic domain of eukaryotic serine/threonine (Ser/Thr) protein kinases (PKs). Eukaryotic PKs are related by a common catalytic domain, consisting of invariant and nearly invariant residues necessary for ATP binding and phosphotransfer. We demonstrate that rather than a Ser/Thr kinase, stk encodes a eukaryotic-like tyrosine (Tyr) kinase. An affinity-purified recombinant Stk (rStk) autophosphorylates and catalyzes the phosphorylation of an artificial substrate on Tyr residues and not on Ser or Thr residues. A change of an invariant lysine within the putative catalytic domain abolishes this kinase activity, indicating that Stk uses a phosphotransfer mechanism similar to the mechanism used by eukaryotic PKs. We provide evidence suggesting that stk is cotranscribed with cI from the phage promoter responsible for maintaining CI expression during lysogeny. The stk gene was identified in prophages obtained from independently isolated Stx-producing Escherichia coli clinical isolates, suggesting that selective pressure has maintained the stk gene in these pathogenic bacteria.

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“…This region in 933W contains the stk gene (48), and in it contains the rexAB genes. In , RexAB proteins are coordinately expressed with the CI repressor from a transcript initiating at the phage p RM promoter (52,57). In addition, rexB can be expressed independently of rexA by transcription initiating at a rexB-associated promoter (33).…”

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Characterization of a Eukaryotic-Like Tyrosine Protein Kinase Expressed by the Shiga Toxin-Encoding Bacteriophage 933W

Tyler

Friedman

2004

J Bacteriol

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“…The time of lag period (2 hrs) may be required for accumulation of the anti-repressor. Recently, it was also found that an anti-repressor, which promotes lytic response of infecting wild type A phage is produced by ACIts857susNO lysogen (Oppenheim et al 1970;Neubauer and Calef 1970;Eisen et al 1970), by defective lysogen harboring several early genes (Spiegelman 1971) and by Avlv3 of Jacob and Wollman (1954) (Sly and Rabideau 1969; Data were not shown in their paper).…”

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PROPHAGE INDUCTION BY THE PRODUCT OF <i>X</i> REGION OF SUPERINFECTED λ OPERATOR-MUTANTS

Murotsu

Horiuchi

1971

The Japanese journal of genetics

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“…In bacteriophage X, two different repressor proteins (the products of genes cI and cro) compete for the chance to act on a single operator region. Once a critical threshold concentration of either protein is achieved, its binding to the common operator blocks synthesis of the other (21,22). Recombinational switches have also evolved and may be more common than physiological switches.…”

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Control of gene expression by a mobile recombinational switch.

Berg¹

1980

Proc. Natl. Acad. Sci. U.S.A.

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Transposable recombinational switches may play important roles in the evolution of bacterial populations by increasing flexibility in the control of expression of particular genes and thereby maintaining heterogeneity in clones of cells growing in a unform environment. Experiments reported here show that Tn5-112, a deletion derivative of kanamycin-resistance transposon Tn5, can function as such a mobile recombinational switch. The internal deletion in Tn5-112 removes transcription termination signals and permits transcription initiated within the element to continue into nearby bacterial genes. Consequently, in one orientation Tn5-112 stimulates distal gene expression, whereas in the other orientation the normal polarity imposed by wild-type Tn5 intervenes and distal gene expression is not stimulated. Because Tn5-112 contains terminal inverted repeats, intramolecular recombination can invert the Tn5-112 element and alter gene expression. Tn5-112 is transposition deficient. Its mobility derives from the recessive nature of the transposition deficiency and, in this study, from the possibility of homologous recombination which permits its placement in either orientation at any site occupied by another Tn5 element. The first demonstration of transposable elements came from analyses of mutable loci in maize. Discrete genetic elements that could move from site to site were recognized as agents that induced chromosome aberrations and that modified the activity of genes near their sites of insertion in a developmentally regulated fashion. It was suggested that such elements might also control the activities of many genes during normal development (1,2).The many recently discovered bacterial transposons (3, 4) led to the intriguing evolutionary concept of genome plasticity-that genes can be gained, lost, or shifted to new positions by processes that do not require extensive nucleotide sequence homology. The potential involvement of transposons in the evolution of new regulatory systems is also apparent: These elements create polar mutations which block transcription of genes in an operon distal to their insertion sites (3). Two transposons (IS2 and Tn3) contain promoters that stimulate the expression of distal genes when the elements are inserted in the correct orientation (5, 6). One transposon (Tn5) stimulates distal gene expression from a fraction of its sites of insertion, independently of its orientation, as if new promoters are created by the fusion of Tn5 with certain target sequences (7).Many transposons contain long terminal inverted repetitions.Because a crossover between inverted repeats inverts interstitial unique sequences (Fig. 1) I report here that Tn5-112, a simple deletion derivative of the kanamycin-resistance transposon Tn5, has gained the ability to act as a recombinational switch which turns on distal gene expression from an internal promoter in one orientation but not in the other. By homologous recombination one can both place in either orientation at any site occupied by another Tn5 elem...

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Two states of expression of genes cl, rex, and N in lambda

Cited by 37 publications

References 21 publications

Characterization of a Eukaryotic-Like Tyrosine Protein Kinase Expressed by the Shiga Toxin-Encoding Bacteriophage 933W

Characterization of a Eukaryotic-Like Tyrosine Protein Kinase Expressed by the Shiga Toxin-Encoding Bacteriophage 933W

PROPHAGE INDUCTION BY THE PRODUCT OF <i>X</i> REGION OF SUPERINFECTED λ OPERATOR-MUTANTS

Control of gene expression by a mobile recombinational switch.

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