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Biomedical subjects

N Delihas

Publications and source records attributed to N Delihas.

49 records · Page 3Linked to original sources

The binding of streptomycin to ribonucleotides.

Incubation of streptomycin (SM) with [32P]5'-ribonucleotides at pH 7.0 produces fractions that migrate towards the cathode in high voltage electrophoresis (HVE) separations at pH 3.5. SM appears to interact with pG, pA and pC but not with pU. The appearance of these [32P]-labeled fractions is dependent on incubation time and SM concentration. Incubation of nucleotides with dihydrostreptomycin (DSM) or SM reduced with sodium cyanoborohydride (NaBH3CN) at pH 5.0, does not produce detectable changes in [32P] nucleotide mobility on HVE; however, incubation with SM reduced with NaBH3CN at pH 7.0 does produce [32P]-labeled fractions migrating with a net positive charge. Elution of [32P]-labeled material migrating towards the cathode from SM-5'-nucleotide incubations and re-electrophoresis results in nucleotides migrating with pG, pA and pC markers. These data indicate a reversible interaction between the SM-streptose aldehyde and amino-group containing nucleotides. This type of interaction may form an additional binding site for SM to RNA, relative to DSM.

Chemical Phenomena↗

Phylogeny of the 5S ribosomal RNA from Synechococcus lividus II: the cyanobacterial/chloroplast 5S RNAs form a common structural class.

The complete nucleotide sequence of the 5S ribosomal RNA from the cyanobacterium Synechococcus lividus II has been determined. The sequence is (sequence in text) This 5S RNA has the cyanobacterial- and chloroplast-specific nucleotide insertion between positions 30 and 31 (using the numbering system of the generalized eubacterial 5S RNA) and the chloroplast-specific nucleotide-deletion signature between positions 34 and 39. The 5S RNA of S. lividus II has 27 base differences compared with the 5S RNA of the related strain S. lividus III. This large difference may reflect an ancient divergence between these two organisms. The electrophoretic mobilities on nondenaturing polyacrylamide gels of renatured 5S RNAs from S. lividus II, S. lividus III, and spinach chloroplasts are identical, but differ considerably from that of Escherichia coli 5S RNA. This most likely reflects differences in higher-order structure between the 5S RNA of E. coli and these cyanobacterial and chloroplast 5S RNAs.

Base Sequence↗