Effects of tetracycline and spectinomycin on the tertiary structure of ribosomal RNA in the Escherichia coli 30 S ribosomal subunit.
Structural analysis of the 16 S rRNA in the 30 S subunit and 70 S ribosome in the presence of ribosome-specific antibiotics was performed to determine whether they produced rRNA structural changes that might provide further insight to their action. An UV cross-linking procedure that determines the pattern and frequency of intramolecular 16 S RNA cross-links was used to detect differences reflecting structural changes. Tetracycline and spectinomycin have specific effects detected by this assay. The presence of tetracycline inhibits the cross-link C967xC1400 completely, increases the frequency of cross-link C1402x1501 twofold, and decreases the cross-link G894xU244 by one-half without affecting other cross-links. Spectinomycin reduces the frequency of the cross-link C934xU1345 by 60% without affecting cross-linking at other sites. The structural changes occur at concentrations at which the antibiotics exert their inhibitory effects. For spectinomycin, the apparent binding site and the affected cross-linking site are distant in the secondary structure but are close in tertiary structure in several recent models, indicating a localized effect. For tetracycline, the apparent binding sites are significantly separated in both the secondary and the three-dimensional structures, suggesting a more regional effect.
Noah
J W
JW
Department of Biochemistry, North Carolina State University, Raleigh, North Carolina 27695-7622, USA.
Dolan
M A
MA
Babin
P
P
Wollenzien
P
P
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D012336:RNA, Ribosomal, 16S / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure*; D012270:Ribosomes / Q000528:radiation effects / Q000648:ultrastructure; D000198:Spectinomycin / Q000494:pharmacology*; D013752:Tetracycline / Q000494:pharmacology*; D014466:Ultraviolet Rays
D000900:Anti-Bacterial Agents; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D000198:Spectinomycin; D013752:Tetracycline