IS1473, a putative insertion sequence identified in the plasmid pAO1 from Arthrobacter nicotinovorans: isolation,...

A putative insertion sequence (IS1473) has been cloned and sequenced. The 1087-bp element was found between the moaA and the ndhA genes in the upstream region of the nicotine dehydrogenase (ndh) operon in the 160-kb pAO1 plasmid of Arthrobacter nicotinovorans. It is flanked by an imperfect repeat of 33 bp and carries two overlapping open reading frames which, by programmed -1 translational frameshifting, may produce a transposase of 36.735 Da with a pI = 10. 18. The deduced protein is similar to the transposases IS481 and IS1002 from Bordetella and IS476 from Xanthomonas campestris, all members of the IS3 family. The putative insertion element was found as a single copy in the pAO1 plasmid and absent on the chromosome of the A. nicotinovorans genome. Similar sequences were detected by hybridization on total DNA from Arthrobacter globiformis, Arthrobacter ramosus, and Arthrobacter ureafaciens.