Biomaterial Database

E. coli ribosomes with a C912 to U base change in the 16S rRNA are streptomycin resistant. 1986

P E Montandon, and R Wagner, and E Stutz

Resistance to streptomycin (Sm) of Euglena gracilis chloroplasts can be due to a single C to T transition of the 16S rRNA gene in an invariant position which is equivalent to C912 of the Escherichia coli 16S rRNA. Since Euglena chloroplasts cannot be transformed we introduced, by site-directed mutagenesis, a C912 to T transition in the cloned rrnB operon (pKK3535) of E. coli and used this new construct (pEM109) in transformation experiments. Transformed E. coli cells were selected for Sm resistance by colony plating and stepwise increase of Sm up to 25 micrograms/ml of culture medium. Several Sm-resistant colonies were obtained. Ribosomes were isolated from pEM109-transformed Sm-resistant and pKK3535-transformed Sm-sensitive cells. The ribosomes were assayed in vitro for Sm-induced misreading of poly(U) mRNA. We isolated 16S rRNA and sequenced the crucial RNA region by reverse transcription. The results clearly show that ribosomes from Sm-resistant cells correctly read the poly(U) mRNA in the presence of 25 micrograms Sm/ml of reaction mixture and the 16S rRNA contains the C912 to U transition. We conclude that C912 is involved in a translation step(s) which is (are) sensitive to streptomycin.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D003596	Cytosine	A pyrimidine base that is a fundamental unit of nucleic acids.
D004351	Drug Resistance	Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.	Resistance, Drug
D004352	Drug Resistance, Microbial	The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).	Antibiotic Resistance,Antibiotic Resistance, Microbial,Antimicrobial Resistance, Drug,Antimicrobial Drug Resistance,Antimicrobial Drug Resistances,Antimicrobial Resistances, Drug,Drug Antimicrobial Resistance,Drug Antimicrobial Resistances,Drug Resistances, Microbial,Resistance, Antibiotic,Resistance, Drug Antimicrobial,Resistances, Drug Antimicrobial
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005056	Euglena gracilis	A species of fresh-water, flagellated EUKARYOTES in the phylum EUGLENIDA.	Euglena gracili,gracilis, Euglena
D012335	RNA, Ribosomal	The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)	Ribosomal RNA,15S RNA,RNA, 15S
D013307	Streptomycin	An antibiotic produced by the soil actinomycete Streptomyces griseus. It acts by inhibiting the initiation and elongation processes during protein synthesis.	Estreptomicina CEPA,Estreptomicina Clariana,Estreptomicina Normon,Strepto-Fatol,Strepto-Hefa,Streptomycin Grünenthal,Streptomycin Sulfate,Streptomycin Sulfate (2:3) Salt,Streptomycin Sulphate,Streptomycine Panpharma,Strepto Fatol,Strepto Hefa
D014498	Uracil	One of four nucleotide bases in the nucleic acid RNA.