ISSN:
1617-4623
Keywords:
Recombinant DNA
;
Helix-turn-helix motifs
;
In vitro transcription-translation
;
Phage immunity
;
Exonuclease III deletions
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The nucleotide sequence of the 3.4 kb SphI-G fragment that contained the repressor gene (c) of the temperate Streptomyces phage ϕc31 was determined. Analysis of this sequence revealed a large open reading frame with protein coding character and sequence changes in c gene point and deletion mutants identified this as the coding region of the repressor. Two of the mutants studied had undergone deletions of 1.1 kb and 1.4 kb that had occurred across short direct repeats of 6 bp and 11 bp, respectively. Coupled in vitro transcription-translation experiments using the cloned SphI-G fragment and Streptomyces lividans cell free extracts identified a protein product of approximately 72 kDa, in close agreement with that predicted from the nucleotide sequence. A strongly predicted helix-turn-helix motif that may be involved in DNA binding occurred towards the carboxy-terminus of the amino acid sequence. Initial attempts to clone the SphI-G fragment in Streptomyces failed; using information gained from the sequence analysis a smaller segment of this DNA fragment was cloned in S. lividans and conferred immunity to a clear plaque mutant (c1) of ϕc31.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00339591
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