The A subunit of DNA gyrase in mycobacteria is frequently subjected to
splicing events as its gene, gyrA, harbours an insertion encoding an
intein. Investigation of a number of different isolates of Mycobacteri
um kansasii, Mycobacterium malmoense, Mycobacterium marinum, Mycobacte
rium ulcerans and Mycobacterium xenopi demonstrated that the presence
of GyrA inteins is not random but a taxonomic character specific for a
given taxon at a species or subspecies level.