This database provides a list of insertion sequences (IS) isolated from bacteria and archae. It is organized into individual files containing their general features (name, size, origin, family.....) as well as their DNA and potential protein sequences. Some of the entries have been identified as individual elements by their insertion activities but a growing number are included from their description in sequenced bacterial genomes. It also includes certain transposons, in particular, members of the Tn3 family of replicative transposons.

The search engine permits the retrieval and display of individual and groups of ISs based on a combination of their general features.

Two levels of search are available.The simple search option enables the user to sort elements using a limited number of basic items whereas the extensive search offers an additional set of possibilities such as comparisons of the sequences of terminal inverted repeats and a variety of different layout displays. Built in links are provided to a number of related and complementary databases and analysis packages.


At present, only individual sequences can be downloaded one by one for comparison. An on-line BLAST facility is available and in future versions direct access to additional analytical tools will be provided on line.


The ISfinder platform also includes a genome browser, ISbrowser (P. Kichenaradja), allowing visualization of IS in certain genomes and ISsaga, an ensemble of software designed to assist in genome annotation of IS (A. Varani).


Permission:It is not permitted to download the ISfinder database without written authorization. Moreover, it is also not permitted at any time to distribute the database to third parties either individually or as part of web-based software.


Direct submission of ISs is encouraged using the on-line form provided.