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661.
G. Jayaraman T.K.S. Kumar T. Sivaraman W.Y. Lin D.K. Chang C. Yu 《International journal of biological macromolecules》1996,18(4):303-306
The thermal unfolding of an all β-sheet protein, cardiotoxin analogue III, from the Taiwan Cobra (Naja naja atra) is studied at pH 2.0, 4.0 and 6.0. At pH 4.0, using circular dichroism and 1-anilino naphthalene-8-sulphonic acid (ANS) fluorescence binding studies, a stable partially structured intermediate is detected at 90°C 相似文献
662.
Narayanan Rajendran Dieter Jahn Kunthala Jayaraman Mohamed A. Marahiel 《FEMS microbiology letters》1994,115(2-3):191-196
Abstract Pseudomonas fluorescens was subjected to insertion mutagenesis studies using the transposon Tn5-GM to generate mutants deficient in antibacterial activity minus mutants. The transposon located on the temperature-sensitive plasmid pCHR84 was conjugally transferred into the non-pathogenic pseudomonad using the triparental mating procedure. Random integration of Tn 5 -GM into the chromosome of P. fluorescens was achieved by heat ttreatment of the transformed cells at 42°C. Approximately 2% of transconjugants revealed an auxotrophic phenotype indicating efficient integration of the employed transposon into the chromosome of P. fluorescens . One transposon insertion mutant was obtained showing an antibacterial activity minus phenotype. This mutant (MM-7) was found to be defective in the production of an unidentified antibacterial compound against B. subtilis . These results introduce Tn 5 transposon mutagenesis as a new useful tool for the molecular analysis of P. fluorescens . 相似文献
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664.
R. Jayaraman 《Journal of genetics》1995,74(3):85-97
WhenEscherichia coli strain AB1157 is subjected to starvation for threonine or leucine on solid media, threonine-independent or leucine-independent
colonies continue to emerge for several days after plating. This process is strongly streptomycin dependent. Under identical
conditions arginine-independent colonies do not arise when arginine starvation is imposed. Since thethr1 andleuB6 alleles of AB1157 could be classified as ‘leaky’ while theargE3 allele cannot be so classified, there seems to be a correlation between leakiness of mutant genetic markers and post-plating
mutagenesis which counters the effect of the mutations. Some of the threonine-independent variants acquired the ability to
increase the leakiness of otherwise nonleaky markers such asargE3 and permit development of arginine independence in arecA-dependent,lexA-independent manner. I show that these variants harbour a mutation, tentatively namedadi (adaptation inducer), at around 72 min on the genetic map, and that theadi mutation increases the intrinsic leakiness of alacZ (ochre) mutation, perhaps by enhanced translational error. These observations are discussed in relation to the phenomenon
of ‘adaptive’ mutagenesis, its possible mechanism, and its specificity. 相似文献
665.
Summary Mutants of Escherichia coli resistant to nitrofurantoin have been isolated. The mutations, designated nfnA and nfnB were introduced individually into a multiply auxotrophic E. coli F– strain and mapped by conjugation and transduction. nfnA is located at 79.8 min and nfnB at 13.0 min on the E. coli chromosome. 相似文献
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669.
S K Pandian T Somasundaram J Jayaraman M Lakshmanan 《Archives of biochemistry and biophysics》1982,216(2):768-770
The pathogenic effect of cotton blight disease is influenced by Xanthomonas malvacearum toxin. The toxin has been highly purified and the interaction between the toxin and the energy-generating system of mitochondria has been characterized. The results show that the toxin inhibits the ATP-ADP translocase system of the mitochondria. 相似文献
670.