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R P Singhal

Publications and source records attributed to R P Singhal.

At least 37 records · Page 2Linked to original sources
PubMed1982

Computer program for storage and retrieval of the nucleic acid structures: storing and updating of transfer RNA sequences - drawing of the secondary structure for transfer RNA by computer.

The availability of a large number of tRNA sequences has created a need for computer programs to store the data. A program written in FORTRAN language allows one to store tRNA sequences and to retrieve information. The data are stored in such a way that it allows a direct comparison of various tRNA sequences. Moreover, the program draws the 'cloverleaf' structure of any stored tRNA sequence and also provides the characteristics of minor, modified nucleosides and major references. Additions and corrections to the program and stored data can be made easily and an individual does not need computer programming skills to use the program.

Base Sequence↗
PubMed1976

Separation of transfer ribonucleic acids on polystyrene anion exchangers.

The transfer RNA separation by chromatography on strong-base polystyrene exchange materials is examined and compared with the widely used reversed-phase chromatography. Results indicate important differences in some transfer RNA (tRNA) elution patterns by the anion-exchange chromatography, as compared with the reversed-phase chromatography. Transfer RNAs containing hydrophobic groups are adsorbed more strongly. The anion exchanger has twice the number of theoretical plates. Single peaks of tRNA2Glu and tRNA1Phe obtained from the reversed-phase column give multiple peaks only polystyrene anion-exchange chromatography. All six leucine tRNAs (Escherichia coli) and differences in tRNA populations synthesized during early and late stages of the dividing lymphocytes from normal human blood can be characterized by the anion-exchange chromatography. Different separation profiles are obtained by two separation systems for tyrosine tRNAs from mouse liver and mouse-plasma-cell tumor. The results indicate that, in contrast to the reversed-phase chromatography, strong-base-polystyrene anion-exchange chromatography is capable of separating tRNAs with minor structlral differences.

Animals↗
PubMed1976

Changes in transfer ribonucleic acids of Bacillus subtilis during different growth phases.

The transfer ribonucleic acids (tRNAs) of B. subtilis at different growth phases are examined for changes in the composition and the methylation of minor constituents. The composition of the tRNAs indicates about equal amounts of adenosine and uridine, and of guanosine and cytidine. About 3-4 residues are present as modified bases in the average tRNA molecule. The net composition of tRNAs appears to remain unaltered during different growth phases. In vitro methylation of tRNAs indicates lack of methyl groups in both exponentially growing cells and spores. In vivo methylation studies show tRNA methylation occurs during the stationary phase in the absence of net tRNA synthesis. Thus, both in vitro and in vivo methylation indicate that the tRNAs in exponentially growing cells do not contain their full complement of modified bases. More complete modification is noted in tRNAs from stationary cells or spores. Hence, tRNA mofifications in general are preserved with fidelity even in the dormant spore but the possibility is left open that specific modifications of selected isoacceptors of tRNAs may occur.

Bacillus subtilis↗