A family of IS1031 elements in the genome of Acetobacter xylinum: nucleotide sequences and strain distribution.

An insertion sequence (here called IS1031A) from Acetobacter xylinum ATCC 23769 has recently been isolated. This study describes the complete nucleotide sequence of IS1031A as well as the sequences of two novel iso-IS1031 elements, IS1031C and IS1031D, from A. xylinum ATCC 23769. The three ISs are all exactly 930 bp long, have imperfect terminal inverted repeats of 24 bp for IS1031A and 21 bp for IS1031C and IS1031D, are flanked by three base pair direct repeats, and contain an open reading frame encoding a putative basic protein of 278 amino acids. Because of nucleotide substitutions, IS1031C and IS1031D differ from IS1031A by 12.9% while IS1031C differs from IS1031D by only 0.6%. Hybridization analyses of total DNA from nine A. xylinum strains showed that all strains contained IS1031-like elements varying in copy number from three to at least 16. None of three Acetobacter aceti strains examined contained IS1031-like elements. Taken together, the results suggest that A. xylinum contains a family of IS1031 elements with considerably diversified nucleotide sequences.