In Bacillus subtilis, the SatA (Formerly YyaR) Acetyltransferase Detoxifies Streptothricin via Lysine Acetylation.

Autor: Burckhardt RM; Department of Microbiology, University of Georgia, Athens, Georgia, USA., Escalante-Semerena JC; Department of Microbiology, University of Georgia, Athens, Georgia, USA jcescala@uga.edu.
Jazyk: angličtina
Zdroj: Applied and environmental microbiology [Appl Environ Microbiol] 2017 Oct 17; Vol. 83 (21). Date of Electronic Publication: 2017 Oct 17 (Print Publication: 2017).
DOI: 10.1128/AEM.01590-17
Abstrakt: Soil is a complex niche, where survival of microorganisms is at risk due to the presence of antimicrobial agents. Many microbes chemically modify cytotoxic compounds to block their deleterious effects. Streptothricin is a broad-spectrum antibiotic produced by streptomycetes that affects Gram-positive and Gram-negative bacteria alike. Here we identify the SatA (for s treptothricin a ce t yltransferase A , formerly YyaR) enzyme of Bacillus subtilis as the mechanism used by this soil bacterium to detoxify streptothricin. B. subtilis strains lacking satA were susceptible to streptothricin. Ectopic expression of satA + restored streptothricin resistance to B. subtilis satA ( Bs SatA) strains. Purified Bs SatA acetylated streptothricin in vitro at the expense of acetyl-coenzyme A (acetyl-CoA). A single acetyl moiety transferred onto streptothricin by SatA blocked the toxic effects of the antibiotic. SatA bound streptothricin with high affinity ( K d [dissociation constant] = 1 μM), and did not bind acetyl-CoA in the absence of streptothricin. Expression of B. subtilis satA + in Salmonella enterica conferred streptothricin resistance, indicating that SatA was necessary and sufficient to detoxify streptothricin. Using this heterologous system, we showed that the SatA homologue from Bacillus anthracis also had streptothricin acetyltransferase activity. Our data highlight the physiological relevance of lysine acetylation for the survival of B. subtilis in the soil. IMPORTANCE Experimental support is provided for the functional assignment of gene products of the soil-dwelling bacilli Bacillus subtilis and Bacillus anthracis This study focuses on one enzyme that is necessary and sufficient to block the cytotoxic effects of a common soil antibiotic. The enzyme alluded to is a member of a family of proteins that are broadly distributed in all domains of life but poorly studied in B. subtilis and B. anthracis The initial characterization of the enzyme provides insights into its mechanism of catalysis.
(Copyright © 2017 American Society for Microbiology.)
Databáze: MEDLINE
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