Characterisation of a hybrid histidine kinase controlling acetate metabolism in Acinetobacter baumannii

RNA sequencing transcriptomics was performed on a highly multidrug resistant A. baumannii strain belonging to international clone I, AB5075_UW and a transposon insertion inactivated mutant of ABUW_0182 (acmS), which encodes a hybrid histidine kinase.Transcriptomics suggests that AcmS controls expression of the genes involved in short-chain fatty acid metabolism in A. baumannii. Biophysical analyses showed ABUW_0182 binds acetic and propionic acid with affinities in a low micromolar range, suggesting they represent the physiological ligands for this hybrid histidine kinase system. Global transcriptomic profiles of the acmS mutant and the parental A. baumannii strain were compared. The parental and mutant cells were grown to mid exponential phase at 37°C, with shaking. Cell pellets were harvested and the total RNA was extracted from three biological replicates. Ribosomal RNA was depleted using Ribozero magnetic kit (Bacteria) (Illumina, Inc., USA) and the cDNA library was generated using Truseq stranded RNA preparation kit (Illumina, Inc., USA). RNA libraries were prepared for sequencing using standard Illumina protocols.