Related Experiment Video
Updated: Jul 12, 2026
11:12
Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach
Published on: September 11, 2017
Target specificity of insertion element IS30
1Biozentrum der Universität Basel, Abteilung Mikrobiologie, Basle, Switzerland. olasz@hubi.abc.hu
Molecular Microbiology
|June 27, 1998
Summary
The mobile element IS30 in Escherichia coli shows high target specificity, inserting into a preferred 24-bp palindromic sequence. This consensus region dictates insertion sites, with variations affecting target activity.
Area of Science:
- Molecular Biology
- Genetics
- Microbiology
Background:
- The mobile genetic element IS30 in Escherichia coli exhibits remarkable target specificity.
- Transposition of IS30 frequently results in insertion at precise locations within preferred target sequences.
Purpose of the Study:
- To elucidate the molecular basis of IS30's target specificity.
- To identify the DNA sequence features governing IS30 insertion site selection.
Main Methods:
- Analysis of known IS30 insertion sites in various genetic elements (phages, plasmids, E. coli genome).
- Characterization of the consensus sequence at insertion sites.
- Quantitative analysis of target site attractiveness in competitive systems.
Main Results:
- IS30 insertion sites are characterized by a long (24-bp) palindromic consensus sequence.
- This consensus region alone determines target DNA attractiveness and insertion position.
- Target site divergence from the consensus and specific base variations influence insertion activity.
- The consensus sequence was the most efficient target in competitive scenarios.
Conclusions:
- IS30 target selection is primarily driven by a specific long palindromic DNA sequence.
- This specificity mechanism may represent an alternative strategy for mobile element target selection.
- Similar target specificity may be characteristic of related insertion sequences like IS3, IS6, and IS21.
Related Concept Videos
02:57DNA-only Transposons
DNA-only transposons are called autonomous transposons since they code for the enzyme transposase that is required for the transposition mechanism. Insertion of transposons can alter gene functions in multiple ways. They can mutate the gene, alter gene expression by introducing a novel promoter or insulator sequence, introduce new splice sites, and change the mRNA transcripts produced, or remodel chromatin structure.
The donor site from where the transposon is excised is either degraded or...
The donor site from where the transposon is excised is either degraded or...
02:53Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...