Evolutionary divergence among species of the yeast genus Saccharomyces was estimated from measurements of deoxyribonucleic acid (DNA)/DNA and ribosomal ribonucleic acid (RNA)/DNA homology. Much diversity was found in the DNA base sequences with several species showing little or no homology to the three reference species, S. cerevisiae, S. lactis, and S. fragilis. These three reference species a...

A temperature-sensitive mutant of Escherichia coli was isolated that had a temperature-sensitive defect in ribosomal-wash protein(s) required for translation in vitro of E. coli endogenous messenger ribonucleic acid. It was found that 30S ribosomal protein S1 rescued the defect in the ribosomal-wash protein(s) of the mutant and that the complete restoration to the wild-type level was attained w...

Background: Traditional dairy products are the main sources for probiotic bacteria. This study aimed to isolate and characterize the potentially probiotic Lactobacillus strains isolated from traditional dairy products in Iran. Methods: Microbial population of each dairy product was enriched and screened for acid- and bile- resistant strains. The isolates were ...

Pyridoxineless mutants of Escherichia coli B stopped incorporation of nucleosides into trichloroacetic acid-insoluble material about 40 to 60 min after pyridoxine starvation was initiated, whereas incorporation of amino acids (measured the same way) slowed but did not stop for several hours. Both these incorporations and cell density were increased most effectively by the presence of either thr...

The effect of chloramphenicol on the synthesis and accumulation of ribonucleic acid (RNA) in Bacillus subtilis was studied. In the presence of chloramphenicol, transfer RNA and ribosomal RNA were synthesized as rapidly 2 to 3 hr after challenge as they were just prior to the addition of the antibiotic. However, under the same conditions, net RNA accumulation ceased after only 30 to 45 min. The ...

  Dysfunction of ribosome biogenesis is commonly found in cancers. Because the transcription of ribosomal RNA genes (rDNA) is a rate-limiting step in ribosome biogenesis and is elevated in many cancer cells, ribosomal RNA transcription can be a target for cancer therapy. In eukaryotes, ribosomal RNA is transcribed specifically in nucleoli by RNA polymerase I but not by RNA polymerase II. Theref...