ZmaR, a novel and widespread antibiotic resistance determinant that acetylates zwittermicin A.
ZmaR is a resistance determinant of unusual abundance in the environment and confers on gram-positive and gram-negative bacteria resistance to zwittermicin A, a novel broad-spectrum antibiotic produced by species of Bacillus. The ZmaR protein has no sequence similarity to proteins of known function; thus, the purpose of the present study was to determine the function of ZmaR in vitro. Cell extracts of E. coli containing zmaR inactivated zwittermicin A by covalent modification. Chemical analysis of inactivated zwittermicin A by 1H NMR, 13C NMR, and high- and low-resolution mass spectrometry demonstrated that the inactivated zwittermicin A was acetylated. Purified ZmaR protein inactivated zwittermicin A, and biochemical assays for acetyltransferase activity with [14C]acetyl coenzyme A demonstrated that ZmaR catalyzes the acetylation of zwittermicin A with acetyl coenzyme A as a donor group, suggesting that ZmaR may constitute a new class of acetyltransferases. Our results allow us to assign a biochemical function to a resistance protein that has no sequence similarity to proteins of known function, contributing fundamental knowledge to the fields of antibiotic resistance and protein function.
Stohl
E A
EA
Department of Plant Pathology, University of Wisconsin, Madison, Wisconsin 53706, USA.
Brady
S F
SF
Clardy
J
J
Handelsman
J
J
D000107:Acetylation; D000123:Acetyltransferases / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D004352:Drug Resistance, Microbial; D015394:Molecular Structure; D010455:Peptides
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D010455:Peptides; C088290:zwittermicin A; D000123:Acetyltransferases; C100968:ZmaR protein, Bacillus