Search PubMed⌕ Search

Biomedical subjects

R M Bock

Publications and source records attributed to R M Bock.

At least 37 records · Page 2Linked to original sources
PubMed1971

Cross-linked transfer RNA functions in all steps of the translation process.

A specific photochemical reaction between 4-thiouridine and cytosine cross-links two arms of transfer RNA. This cross-link, introduced into phenylalanine transfer RNA and arginine transfer RNA, limits the conformational freedom of the molecule. Both modified transfer RNA's are capable of functioning in all steps of protein synthesis with this restraint on allowable conformations.

Arginine↗
PubMed1971

Chemical modifications of transfer RNA species. Desulfurization with Raney nickel.

A single, modified nucleoside in Escherichia coli tRNA, 6-(3-methyl-2-butenylamino)-2-methyl-thio-9-beta-D-ribofuranosylpurine, has been desulfurized with Raney nickel to afford its probable biosynthetic precursor. The limitations of the reaction at the nucleoside and tRNA levels and its lack of inhibition of the amino acid acceptor activity of tRNA are described.

Catalysis↗
PubMed1971

Cytokinins: development of a potent antagonist.

A systematic search has resulted in the synthesis of a class of cytokinin antimetabolites. The development and biological properties of the anticytokinins are discussed in terms of one member of the class, 3- methyl - 7 - (3 - methylbutylamino)pyrazolo[4,3 - d]- pyrimidine.

Antimetabolites↗
PubMed1969

Cytokinins: distribution in species of yeast transfer RNA.

Transfer RNA fractions from Saccharomyces lactis and Saccharomyces cerevisiae have been tested for cytokinin activity in the tobacco bioassay. Cysteine tRNA has been identified as a cytokinin-containing tRNA species in S. cerevisiae. Acid hydrolysates of S. lactis tRNA fractions (containing arginine tryptophan, and valine acceptor activities) and S. cerevisiae tRNA fractions (containing alanine, asparagine, aspartic acid, glutamic acid, glycine, histidine, tryptophan, and valine acceptor activities) were inactive in the tobacco bioassay. Cytokinins have been found only in those tRNA species corresponding to codons beginning with U.

Biological Assay↗
PubMed1968

Single crystals of transfer RNA from formylmethionine and phenylalanine transfer RNA's.

Reproducible conditions have been developed for crystallization of transfer RNA. The conditions may be applicable to many pure transfer RNA species since identical procedures (except for initial transfer-RNA concentration) yielded good crystals from both yeast and Escherichia coli transfer RNA. These crystals, which must be kept at temperatures below about 10 degrees C and handled in vapor of controlled alcohol concentration, have been studied by x-ray crystallography. The availability of crystals of a nucleic acid opens a route for extending knowledge of the tertiary structure of transfer RNA and its relation to important biological functions.

Chemical Phenomena↗