Kuan Chih Chow

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The influence of the nucleotide at position -3 relative to the AUG initiation codon on the initiation of protein synthesis was studied in two different in vitro translation systems using synthetic mRNAs. The four mRNAs, transcribed from cDNAs directed by an SP6 promoter, were identical except for mutations at nucleotide -3. In each case, translation of(More)
A 1.47-kb DNA fragment that carries the tryptophanyl-tRNA synthetase (TrpRS) gene of Bacillus subtilis has been cloned into the pUC8 plasmid. The recombinant plasmid, pTSQ2, conferred temperature-resistance to the temperature-sensitive trpS ts mutant of B. subtilis through chromosomal transformation, and to that of Escherichia coli through complementation.(More)
We have developed a specific, sensitive, and quantitative assay for topoisomerase I, which is based on the formation of a covalent enzyme-DNA intermediate. Our assay measures the quantitative transfer of 32P radioactivity from 32P-labeled DNA to topoisomerase I. Since 32P-labeled topoisomerase molecules are resolved by NaDodSO4/PAGE, HeLa topoisomerase I(More)
In our earlier experiments, we discovered that magnetic field exposure could bring both stabilizing and destabilizing effects to the DNA of Escherichia coli, depending on our parameters of assessment, and both of these effects were associated with the induced synthesis of the heat shock proteins Hsp70/Hsp40 (DnaK/DnaJ). These contradicting results prompted(More)
The thermal transitions of Halobacterium cutirubrum have been examined by differential scanning calorimetry. Two distinct peaks corresponding to the denaturation of two major protein components were observed in the heating curves. One of the peaks has been assigned to the denaturation of the envelope glycoprotein. The variations of the denaturation(More)
In contrast to the common impression that exposure to a magnetic field of low frequency causes mutations to organisms, we have demonstrated that a magnetic field can actually enhance the efficiency of DNA repair. Using Escherichia coli strain XL-1 Blue as the host and plasmid pUC8 that had been mutagenized by hydroxylamine as the vector for assessment, we(More)
Like some naturally occurring environmental stress factors such as heat shock and UV irradiation, magnetic field exposure is also stimulatory to transposition activity. This feature could be illustrated by a bacterial conjugation study using an Escherichia coli strain that carries the transposable element Tn5 as the donor. When the donor cultures were(More)
Polyadenylated RNA was isolated from Orgyia pseudotsugata larvae 8-10 days postinfection with the multicapsid nuclear polyhedrosis virus. This RNA was centrifuged through a sucrose gradient and fractions enriched for polyhedrin mRNA were identified by in vitro translation. Complementary DNA made to this RNA hybridized predominantly to a 5-kb fragment of(More)