Pn. Rather et E. Orosz, CHARACTERIZATION OF AARA, A PLEIOTROPIC NEGATIVE REGULATOR OF THE 2'-N-ACETYLTRANSFERASE IN PROVIDENCIA-STUARTII, Journal of bacteriology, 176(16), 1994, pp. 5140-5144
We have utilized transposon mutagenesis to obtain insertional mutation
s in Providencia stuartii that activate the chromosomal aac(2')-la gen
e. Two closely linked mini-Tn5Cm insertions were obtained in a locus d
esignated aarA, and a single insertion was obtained in a separate locu
s, aarC. Nucleotide sequence analysis, complementation studies, and lo
calization of the sites of mini-Tn5Cm insertion have allowed the ident
ification of the aarA coding region. The deduced AarA protein had a mo
lecular mass of 31,086 kDa and displayed characteristics of an integra
l membrane protein. A strain deleted for the aarA gene by allelic exch
ange showed at least a fourfold increase in the accumulation of aac(2'
)-la mRNA and an eightfold increase in aminoglycoside resistance. Muta
tions in aarA were pleiotrophic and also resulted in loss of pigmentat
ion and a deficiency in cell separation during division.