Skip to Main content Skip to Navigation

Homologous recombination at the border: Insertion-deletions and the trapping of foreign DNA in Streptococcus pneumoniae

Abstract : Integration of foreign DNA was observed in the Gram-positive human pathogen Streptococcus pneumoniae (pneumococcus) after transformation with DNA from a recombinant Escherichia coli bacteriophage lamda carrying a pneumococcal insert. Segments of lamda DNA replaced chromosomal sequences adjacent to the region homologous with the pneumococcal insert, whence the name insertion-deletion. Here we report that a pneumococcal insert was absolutely required for insertion-deletion formation, but could be as short as 153 bp; that the sizes of foreign DNA insertions (289-2,474 bp) and concomitant chromosomal deletions (45-1,485 bp) were not obviously correlated; that novel joints clustered preferentially within segments of high GC content; and that the crossovers in 29 independent novel joints were located 1 bp from the border or within short (3-10 nt long) stretches of identity (microhomology) between resident and foreign DNA. The data are consistent with a model in which the insert serving as a homologous recombination anchor favors interaction and subsequent illegitimate recombination events at microhomologies between foreign and resident sequences. The potential of homology- directed illegitimate recombination for genome evolution was illustrated by the trapping of functional heterologous genes.
Document type :
Journal articles
Complete list of metadatas

https://hal.univ-lorraine.fr/hal-01797918
Contributor : Virginie Libante <>
Submitted on : Tuesday, May 22, 2018 - 10:47:44 PM
Last modification on : Friday, January 10, 2020 - 9:08:31 PM

Links full text

Identifiers

Collections

Citation

Marc Prudhomme, Virginie Libante, Jean-Pierre Claverys. Homologous recombination at the border: Insertion-deletions and the trapping of foreign DNA in Streptococcus pneumoniae. Proceedings of the National Academy of Sciences of the United States of America , National Academy of Sciences, 2002, 99 (4), pp.2100 - 2105. ⟨10.1073/pnas.032262999⟩. ⟨hal-01797918⟩

Share

Metrics

Record views

56