A bacterial genome in transition--an exceptional enrichment of IS elements but lack of evidence for recent transposition in the symbiont Amoebophilus asiaticus.

ABSTRACT:

Background

Insertion sequence (IS) elements are important mediators of genome plasticity and are widespread among bacterial and archaeal genomes. The 1.88 Mbp genome of the obligate intracellular amoeba symbiont Amoebophilus asiaticus contains an unusually large number of transposase genes (n = 354; 23% of all genes).

Results

The transposase genes in the A. asiaticus genome can be assigned to 16 different IS elements termed ISCaa1 to ISCaa16, which are represented by 2 to 24 full-length copies, respectively. Despite this high IS element load, the A. asiaticus genome displays a GC skew pattern typical for most bacterial genomes, indicating that no major rearrangements have occurred recently. Additionally, the high sequence divergence of some IS elements, the high number of tr

SUBMITTER: Schmitz-Esser S 

PROVIDER: S-EPMC3196728 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature