30s subunit Flashcards
Which of these antibiotics target 30s subunit? A. Ketolides B. Aminoglycosides C. Tetracyclines D. Spectinomycin
B,C, and D
Aminoglycosides can bind __________of the bacterial cell wall?
negatively charged lipopolysaccharide
What targets the A site with the 16s rRNA 30s subunit?
Aminoglycosides
What is the main target for the majority of aminoglycosides?
Internal loop Helix 44 of 16s rRNA, the P ste
Paromomycin fixes the flexible A1492 and A1493 in a conformation similar to induced fit by cognate aminoacyl-tRNA, this will do what to the protein?
Mutate the protein due to the fact that the 30s Subunit will close around a near cognate and result in the wrong amino acid.
Which aminoglycoside is said to be used to treat cystic fibrosis?
Gentamicin
Kanamycin and ___________ are prone to____________.
tobramycin; dimerization
Dimers cause inhibition of the 30s and 50s subunit interaction, which antibiotic duo does that?
Kanamycin and tobramycin
Which stage of translation is the dimer interaction of kanamycin and tobramycin most likely to affect? A. Elongation 1 B. Recycling C. Termination D. Initiation 3
D. Initiation 3
Streptomycin binds close to which helix?
Helix 27
Streptomycin is the only aminoglycoside to possess which of these?
- streptindine back bone
- two sugar molecules
- a polar aryl
- None of the above.
A streptidine backbone
Ribosomal protein S12 is involved ?
with streptomycin, the formation of the closed structure 30s upon binding a cognate aminoacyl-tRNA
Streptomycin inhibits which stage of initiation?
Initiation II
Which of these antibiotics prevent the normal dissociation of ribosomes? A. Erythromycin B. Tobramycin C. Streptomycin D. Kanamycin
C. Streptomycin
Which antibiotic is used to cure tuberculosis?
Streptomycin
What region of the 50s has been reported to interact with aminoglycosides?
Helix 69
When H44 is already saturated, which region do aminoglycosides bind to?
Helix 69
What antibiotics interact with H69 of the 50S resulting in inhibition of 70S dissociation.
Neomycin, gentamicin and paromomycin
What explains the side effects of aminoglycosides.?
A1408
T or F: Aminoglycosides are known to accumulate in the perilymph and endolymph of the inner ear and at high concentrations damage hair cells.
True
Which antibiotic binds the 16S rRNA of the 30S in the helix 34 (H34)
Spectinomycin
T and F: Spectinomycin binds to H34 and sterically blocks movement causing inhibition of translocation.
True
T or F: Tetracycline binds at Tet-2 site on 16s rRNA
False; Tetracycline binds at Tet-1
What does tetracycline prevent from occurring?
A. Prevent physical binding to P site
B. Prevent physical binding to A site
C . Prevent physical transfer of peptidyl bond
D. Prevent physical transfer of peptidyl bond to E site
B. Prevent physical binding to A site.
Which of the 4 proteins does tetracycline interact with ?
A. S4 for Tet-2; S7 for Tet-6, S9 for Tet-4 and S17 for Tet-5
B. S1 for Tet-2; S7 for Tet-6, S9 for Tet-4 and S17 for Tet-5
C. S4 for Tet-2; S7 for Tet-6, S9 for Tet-4 and S10 for Tet-5
D. S4 for Tet-2; S10 for Tet-6, S9 for Tet-4 and S17 for Tet-5
A. S4 for Tet-2; S7 for Tet-6, S9 for Tet-4 and S17 for Tet-5
T or F: All tetracycline binding sites could act synergistically to contribute to the strong bacteriostatic effect of tetracycline
True
One of the most interesting forms of resistance to tetracyclines is?
Ribosomal protection:. It has been proposed that Tet-M binds to the A-site and actively releases tetracycline bound to it.
What antibiotic is bacteriostatic at low concentrations and bactericidal at high concentrations
Mupirocin
Isoleucine-tRNA-synthetase (IleRS)
is inactivated by which antibiotic?
Why?
Mupirocin; it mimics the IIeRS substrate
