Whole-genome organization and functional properties of miniature DNA insertion sequences conserved in pathogenic Neisseriae

Short RNAs Can Identify New Candidate Transposable Element Families in Arabidopsis

“…These are abundant, small DNA insertion sequences in the chromosome of the pathogenic bacterium Neisseriae gonorrhoeae (Mazzone et al, 2001). Unit length nemis (approximately 160 bp) feature TIRs (26-27 bp) and can potentially fold into a robust stem-loop structure.…”

The abundant class of nemis repeats provides RNA substrates for ribonuclease III in Neisseriae

“…Both the abundance and the peculiar pattern of interspersion suggest that nemis may have regulatory functions. The hypothesis that these repeats may influence gene expression is supported by the finding that in 7/7 N. meningitidis genes analyzed, the 5Vtermini of the gene transcripts lye within flanking nemis sequences [4].…”

“…Of these, many are variously combined in intergenic repeat arrays plausibly involved in recombination processes frequently occurring in Neisseriae [1]. Other DNA repeats, as the so-called Correia [3] or nemis [4] sequences, are predominantly found as individual units. Nemis are miniature DNA insertion sequences (80-160 bp), which feature 26 -27 bp long terminal inverted repeats (TIRs).…”

“…Nemis are miniature DNA insertion sequences (80-160 bp), which feature 26 -27 bp long terminal inverted repeats (TIRs). The presence of target site duplications at nemis ends, and the identification in sequenced strains of homologous chromosomal regions containing or lacking nemis DNA, both indicate that nemis are (or have been) mobile genetic elements [4]. Both transposition and recombination events contributed to the genomic spread of this unusual class of DNA repeat family, which is organized in a few major structural subsets and includes, both in A and B serogroup meningococci, f 300 members.…”

“…Both transposition and recombination events contributed to the genomic spread of this unusual class of DNA repeat family, which is organized in a few major structural subsets and includes, both in A and B serogroup meningococci, f 300 members. Of these, about two-thirds are interspersed with single-copy DNA, and inserted at close distance from coding regions [4]. Both the abundance and the peculiar pattern of interspersion suggest that nemis may have regulatory functions.…”