5it8
From Proteopedia
High-resolution structure of the Escherichia coli ribosome
Structural highlights
FunctionRS5_ECOLI With S4 and S12 plays an important role in translational accuracy. Many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations).[1] Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body.[2] The physical location of this protein suggests it may also play a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp.[3] Publication Abstract from PubMedMutations conferring resistance to translation inhibitors often alter the structure of rRNA. Reduced susceptibility to distinct structural antibiotic classes may, therefore, emerge when a common ribosomal binding site is perturbed, which significantly reduces the clinical utility of these agents. The translation inhibitors negamycin and tetracycline interfere with tRNA binding to the aminoacyl-tRNA site on the small 30S ribosomal subunit. However, two negamycin resistance mutations display unexpected differential antibiotic susceptibility profiles. Mutant U1060A in 16S Escherichia coli rRNA is resistant to both antibiotics, whereas mutant U1052G is simultaneously resistant to negamycin and hypersusceptible to tetracycline. Using a combination of microbiological, biochemical, single-molecule fluorescence transfer experiments, and X-ray crystallography, we define the specific structural defects in the U1052G mutant 70S E. coli ribosome that explain its divergent negamycin and tetracycline susceptibility profiles. Unexpectedly, the U1052G mutant ribosome possesses a second tetracycline binding site that correlates with its hypersusceptibility. The creation of a previously unidentified antibiotic binding site raises the prospect of identifying similar phenomena in antibiotic-resistant pathogens in the future. Resistance mutations generate divergent antibiotic susceptibility profiles against translation inhibitors.,Cocozaki AI, Altman RB, Huang J, Buurman ET, Kazmirski SL, Doig P, Prince DB, Blanchard SC, Cate JH, Ferguson AD Proc Natl Acad Sci U S A. 2016 Jul 19;113(29):8188-93. doi:, 10.1073/pnas.1605127113. Epub 2016 Jul 5. PMID:27382179[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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