Reaction of nucleic acid bases with alpha-acetylenic esters. Part IV. Preparation of an alkylating derivative of tRNA(Phe) by conformation-specific chemical modification.
The reaction of yeast tRNA(Phe) with methyl chlorotetrolate, ClCH2-C identical to C-COOCH3, was studied. This reagent converts adenine and cytosine rings into derivatives in which an additional heterocycle bearing the alkylating chloromethyl group is fused to the original base; these derivatives can exist in two isomeric forms. Modified nucleosides of this type can be easily identified by reverse-phase HPLC. It was found that under native conditions, the modification of tRNA involves the anticodon loop and the 3'-end. The isomers of adenine derivatives formed in the anticodon loop were different from those formed in the 3'-end. It is suggested that the isomeric structure of the derivatives is related to the fine conformational differences between these two regions of tRNA(Phe). Methyl chlorotetrolate could thus be used as a conformational probe of single-stranded nucleic acids. Preliminary assays showed that modified tRNA(Phe) binds irreversibly to yeast phenylalanyl-tRNA synthetase.
Roques
P
P
Laboratoire de Biochimie Cellulaire, Collège de France, Paris.
Thomé
F
F
Olomucki
M
M
D000478:Alkylation; D000480:Alkynes / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation / Q000187:drug effects*; D010652:Phenylalanine-tRNA Ligase / Q000378:metabolism; D012331:RNA, Fungal / Q000378:metabolism; D012345:RNA, Transfer, Amino Acid-Specific / Q000378:metabolism; D012360:RNA, Transfer, Phe / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics
D000480:Alkynes; D012331:RNA, Fungal; D012345:RNA, Transfer, Amino Acid-Specific; D012360:RNA, Transfer, Phe; C051334:methyl chlorotetrolate; D010652:Phenylalanine-tRNA Ligase