Supplementary file 1_Metabolic versatility of Acinetobacter baumannii: distinct pathways for the utilization of short-, medium- and long-chain acyl-L-carnitines.docx

Its cellular localization in the cytoplasm was demonstrated. The purified ACH exhibited no enzymatic activity toward long-chain acyl-L-carnitines. However, growth experiments revealed that both the wild type and the Δach mutant were able to grow clearly on these substrates, providing evidence for the involvement of an additional, as-yet-uncharacterized enzyme.

The cell culture supernatant was used for the chromatographic enrichment of a protein fraction showing robust enzyme activity for the hydrolysis of long-chain acyl-L-carnitines. Proteomic analysis of a partially purified hydrolase fraction and of the A. baumannii secretome revealed the gene product of open reading frame HMPREF0010_02333 as a hydrolase candidate. The respective protein was recombinantly overproduced and purified and its ability to cleave various long-chain acyl-L-carnitines was demonstrated.

Based on the substrate specificity of the characterized ACH from the cytosol and the acyl-L-carnitine hydrolase present in the culture supernatant (ACHS), a metabolic model for the versatile utilization of small- medium- and long-chain acyl-L-carnitines by A. baumannii was proposed.</p>