Aminoglycoside antibiotics are able to specifically bind the 5'-untranslated region of thymidylate synthase messenger RNA.
The translational initiation codon for thymidylate synthase (TS) mRNA is located in a unique stem-loop structure which contains an internal cytosine-cytosine (CC) bubble. This stem-loop structure is thought to be important in the regulation of TS translation, which is itself an important target for anticancer drugs, such as 5-fluorouracil. Internal bubble or bulge structures are candidate receptors for the aminoglycoside antibiotics. It is shown here that aminoglycosides bind in a specific and saturable fashion with dissociation constants of approximately 1 microM to a TS mRNA site 1 construct and that the binding site for the aminoglycosides is located in the CC bubble region. In fact, the CC bubble, when grafted into other stem-loop structures, confers aminoglycoside binding on them. These studies reveal an additional binding domain for aminoglycosides and also suggest how novel anti-cancer drugs might be designed that affect TS mRNA translation rather than enzyme function.
Tok
J B
JB
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Cho
J
J
Rando
R R
RR
D020121:5' Untranslated Regions / Q000737:chemistry*; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001665:Binding Sites / Q000235:genetics; D018983:DNA Footprinting; D004252:DNA Mutational Analysis; D016297:Mutagenesis, Site-Directed; D009355:Neomycin / Q000737:chemistry; D012333:RNA, Messenger / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry; D012260:Ribonucleases / Q000737:chemistry; D013403:Sugar Phosphates / Q000737:chemistry; D013940:Thymidylate Synthase / Q000737:chemistry / Q000235:genetics*
D020121:5' Untranslated Regions; D000900:Anti-Bacterial Agents; D012333:RNA, Messenger; D012235:Rhodamines; D013403:Sugar Phosphates; D013940:Thymidylate Synthase; D012260:Ribonucleases; D009355:Neomycin