Genetic structure, function and regulation of the transposable element IS21.

Détails

ID Serval
serval:BIB_3A83B8B1CEF7
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Genetic structure, function and regulation of the transposable element IS21.
Périodique
Molecular and General Genetics
Auteur(s)
Reimmann C., Moore R., Little S., Savioz A., Willetts N.S., Haas D.
ISSN
0026-8925 (Print)
ISSN-L
0026-8925
Statut éditorial
Publié
Date de publication
1989
Volume
215
Numéro
3
Pages
416-424
Langue
anglais
Résumé
The IncP plasmid R68.45 and other plasmids carrying tandem repeats of the insertion sequence IS21 [= (IS21)2] produce replicon fusions via transposition at high frequencies in Escherichia coli and other gram-negative bacteria, whereas plasmids with a single IS21 copy, e.g. R68, give replicon fusions rarely. The 2131 bp nucleotide sequence of IS21 was determined; at the ends there were 11 bp inverted repeats with one mismatch. Two adjacent open reading frames, istA and istB, were located on one DNA strand of IS21. In E. coli maxicells, polypeptides of 46 kDa (the istA gene product) and 30 kDa (the istB gene product) were expressed by (IS21)2 plasmids, but not by IS21 plasmids. Genetic analysis of (IS21)2 plasmids indicates that the IS21-IS21 junctions form a promoter, which initiates transcription of the istAB operon in one of the two IS21 elements. A single IS21 element fused to an inducible external tac promoter expressed both proteins after induction, but did not promote effective replicon fusion, unless an IS21-IS21 junction (the preferred site for IS21 transposase action) was also present on the plasmid carrying the tac-IS21 construct. The sequences located between the IS21 elements in (IS21)2, 3 bp in R68.45 or 2 bp in pME28, were not recovered in the replicon fusion products. Homologous recombination between the directly oriented IS21 elements in the fusion products led to plasmids with a single IS21 insertion. Analysis of the latter showed that IS21 had a low, but not totally random specificity of insertion and created target duplications of 4 bp (occasionally 5 bp).(ABSTRACT TRUNCATED AT 250 WORDS)
Mots-clé
Amino Acid Sequence, Bacterial Proteins/genetics, Base Sequence, DNA Transposable Elements, DNA, Bacterial/genetics, Escherichia coli/genetics, Gene Amplification, Gene Expression Regulation, Genes, Bacterial, Molecular Sequence Data, Plasmids, Promoter Regions, Genetic
Pubmed
Web of science
Création de la notice
24/01/2008 15:00
Dernière modification de la notice
20/08/2019 14:30
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