National Repository of Grey Literature 2 records found  Search took 0.01 seconds. 
Critical sites determining the resistance phenotype of ABC proteins from the ARE subfamily and the molecular mechanism of their function
Lenart, Jakub
Vga(A) and Msr(A) are resistance proteins belonging to the ARE subfamily of ABC -F proteins. They confer resistance to inhibitors of the peptidyltransferase center. It has been proposed that the mechanism of resistance is based on interaction with a transmembrane partner that forms the functional transporter. Their ribosomal function has been described by cryoelectron microscopy of ribosome complexes with ABCF mutants unable to hydrolyze ATP. However, the exact mechanism of resistance is not yet known. We have produced the mutant proteins combining the four amino acid residues in Vga(A) and Vga(A)LC at the linker tip, and we were the first to describe the effects of substrate specificity of the single mutants. Amino acid positions 212 and 220 are important for resistance to lincosamides and pleuromutilins, respectively, while position 219 is responsible for resistance to streptogramin A. Each amino acid property plays a critical role in conferring antibiotic specificity, as confirmed by the fact that amino acid substitution at position K218T in the Vga(A) protein causes the shift in resistance from streptogramins to lincosamides and pleuromutilins. The mechanism of resistance conferred by Vga(A) is ribosomal protection. This is supported by the fact that the rate of [3H]-lincomycin accumulation in...
Critical sites determining the resistance phenotype of ABC proteins from the ARE subfamily and the molecular mechanism of their function
Lenart, Jakub ; Balíková Novotná, Gabriela (advisor) ; Melter, Oto (referee) ; Branny, Pavel (referee)
Vga(A) and Msr(A) are resistance proteins belonging to the ARE subfamily of ABC -F proteins. They confer resistance to inhibitors of the peptidyltransferase center. It has been proposed that the mechanism of resistance is based on interaction with a transmembrane partner that forms the functional transporter. Their ribosomal function has been described by cryoelectron microscopy of ribosome complexes with ABCF mutants unable to hydrolyze ATP. However, the exact mechanism of resistance is not yet known. We have produced the mutant proteins combining the four amino acid residues in Vga(A) and Vga(A)LC at the linker tip, and we were the first to describe the effects of substrate specificity of the single mutants. Amino acid positions 212 and 220 are important for resistance to lincosamides and pleuromutilins, respectively, while position 219 is responsible for resistance to streptogramin A. Each amino acid property plays a critical role in conferring antibiotic specificity, as confirmed by the fact that amino acid substitution at position K218T in the Vga(A) protein causes the shift in resistance from streptogramins to lincosamides and pleuromutilins. The mechanism of resistance conferred by Vga(A) is ribosomal protection. This is supported by the fact that the rate of [3H]-lincomycin accumulation in...

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