%0 Journal Article
%T Capture of armA by a novel ISCR element, ISCR28.
%A Yuan M
%A Nie L
%A Huang Z
%A Xu S
%A Qiu X
%A Han L
%A Kang Y
%A Li F
%A Yao J
%A Li Q
%A Li H
%A Li D
%A Zhu X
%A Li Z
%J Int J Antimicrob Agents
%V 64
%N 3
%D 2024 Jun 20
%M 38908532
%F 15.441
%R 10.1016/j.ijantimicag.2024.107250
%X ISCR28 is a fully functional and active member of the IS91-like family of insertion sequences. ISCR28 is 1,708-bp long and contains a 1,293-bp long putative open reading frame that codes a transposase. Sixty ISCR28-containing sequences from GenBank generated 27 non-repeat genetic contexts, all of which represented naturally occurring biological events that had occurred in a wide range of gram-negative organisms. Insertion of ISCR28 into target DNA preferred the presence of a 5'-GXXT-3' sequence at its terIS (replication terminator) end. Loss of the first 4 bp of its oriIS (origin of replication) likely caused ISCR28 to be trapped in ISApl1-based transposons or similar structures. Loss of terIS and fusion with a mobile element upstream likely promoted co-transfer of ISCR28 and the downstream resistance genes. ArmA and its downstream intact ISCR28 can be excised from recombinant pKD46 plasmids forming circular intermediates, further elucidating its activity as a transposase.