130 results match your criteria: "Institute Ruder Boskovic[Affiliation]"

The recB21 mutation abolishes the exonuclease activity of the RecBCD enzyme (exonuclease V) of Escherichia coli. This might be due to the polar effect of recB21 on expression of the recD gene, the product of which is an essential component of the RecBCD enzyme. To achieve synthesis of the recD gene product, the recD+ plasmid was introduced into the recB21 mutant.

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The effects of inhibitors on the efflux of ammonia (from the basolateral to the apical side, Jb----a) were studied in preparation of isolated Carcinus gills immersed in dilute seawater (DSW) that was identical to the perfusion solution. Adding 10(-4) M amiloride to the solution bathing the gill preparations reduces the efflux of ammonia by 29% relative to the control value. Under experimental conditions, it appears that only about 1% of the amiloride-sensitive influx of Na+ (Ja----b) can be exchanged with NH4+ on an equimolar basis.

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UV-induced mutagenesis was investigated in the uvrB strain and its isogenic counterpart overproducing the single-stranded DNA-binding protein (SSB). It was demonstrated that overproduction of SSB significantly increases the frequency of mutation. Our results indicate that such an increase might be due to certain abnormalities in induction of the SOS response (untimely and prolonged activation of the RecA protein).

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The investigations were performed with the eggs of the sea urchin speciesSphaerechinus granularis Lam. They were kept at 22° C under continuous aeration for up to 45 hours with stirring to compensate for sedimentation. 1.

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