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Biomedical subjects

M Sprinzl

Publications and source records attributed to M Sprinzl.

At least 163 records · Page 9Linked to original sources
PubMed1975

Proton magnetic resonance studies on the conformation of the hexanucleotide, GmpApApYpApsiP, and Related fragments from the anticodong loop of baker's yeast phenylalanine transfer ribonucleic acid.

A hexanucleotide, GmpApApYpAppsiP, and 11 related compounds from the anticodon loop of Baker's yeast tRNA-Phe were studied by proton magnetic resonance from 100 to 250 MHz. Totally 19 resonance lines from all the base protons (H8, H6, and H2), H1', and methyl proton resonances of the hexamer have been assigned by a systematic "incremental procedure" in comparing all the related shorter fragments. Emphasis is given to the Y base and its stacking conformation with respect to its nearest neighboring bases. The results reveal a strong tendency of the purine bases to have a maximal extent of base-base overlap with their neighbors in the sequence. This tendency is manifested in a zigzag (or balcony-like) mode of base-stacking pattern of the -ApYpA-sequence in the hexamer in which the -pA-residue tends to stack toward the adduct ring (C10, C11, and N12) of Y. This tendency is also shown in the formation of a stack of GmAAA closing the gap left behind by the excision of Y in the hexamer GmpApAp--pApp. The implication of these findings to the structure and function of tRNA is discussed.

Codon↗
PubMed1975

Site of aminoacylation of tRNAs from Escherichia coli with respect to the 2'- or 3'-hydroxyl group of the terminal adenosine.

A method is presented by which the site of primary attachment of the amino acids with respect to the 2'- or 3'-hydroxyl group of the terminal adenosine of E. coli tRNAs can be determined. It is found that the aminoacyl-tRNA synthetases (EC 6.1.1.-) with specificity for Arg, Asn, Ile, Leu, Met, Phe, Thr, Trp, and Val attach the amino acid to the 2'-position; those with specificity for Gly, His, Lys, and Ser attach the amino acid to the 3'-position; and that Tyr and Cys can be enzymatically attached to both the 2'- and 3'-positions. Together with previous experiments on yeast aminoacyl-tRNA synthetases, it is now shown that the specificity for one particular hydroxyl group is preserved during the evolution from prokaryotic to eukaryotic systems.

Adenosine↗
PubMed1975

[Reactivity of the 3'-terminal oligonucleotide Sequence C-A-C-C-A of tRNAPhe and tRNAVal from baker's yeast upon N-oxidation with monoperphthalic acid as compared to the oligonucleotides C-A-C-C-A and A-A-A-U-C-A-C-C-A (author's transl)].

The nucleobases adenine and cytosine were subjected to N-oxidation by monoperphthalic acid at pH 7 and 0 degrees C in tRNAPhe, in the 3'-terminal pentanucleotide C-A-C-C-A from tRNAPhe, as well as in tRNAVal and in the 3'-terminal nonanucleotide A-A-A-U-C-A-C-C-A from tRNAVal. In the tRNAs, the oxidative attack occurs stepwise from the 3'-end. First the 3'-terminal adenine is oxidized, then the following two cytosines, then the following adenine. The oligonucleotides are far more reactive than the identical sequences in tRNA and are not oxidized according to a sequential mechanism.

Base Sequence↗
PubMed1974

A new transfer RNA fragment reaction: Tp psi pCpGp bound to a ribosome-messenger RNA complex induces the synthesis of guanosine tetra- and pentaphosphates.

The tetranucleotide TpPsipCpGp, when bound to Escherichia coli 50S ribosomal subunits, can replace intact tRNA in the stringent factor-directed synthesis of guanosine tetra- and pentaphosphates. The TpPsipCpGp-dependent fragment reaction has a strict requirement for the 50S and 30S ribosomal subunits and synthetic or natural messenger RNA.

Bacterial Proteins↗