Biomaterial Database

23S ribosomal ribonucleic acid of macrolide-producing streptomycetes contains methylated adenine. 1979

M Y Graham, and B Weisblum

Coresistance to macrolide, lincosamide, and streptogramin B-type (MLS) antibiotics by a common biochemical mechanism characterizes clinically resistant pathogens. Of 10 streptomycetes tested for resistance to macrolide, lincosamide, and streptogramin B-type antibiotics, only 1, Streptomyces erythreus, the organism used for production of erythromycin, was found resistant to all three classes; moreover, it was the only streptomycete in the series tested found to contain N6-dimethyladenine (m62A) in 23S ribosomal ribonucleic acid, the structural alteration of ribosomal ribonucleic acid associated with clinical resistance. Of the seven streptomycetes tested for the presence of m62A and N6-methyladenine (m6A), two, S. fradiae and S. cirratus, which produce the macrolide antibiotics tylosin and cirramycin, respectively, were found to contain m6A, but not m62A. The remaining strains tested, including strains which produce lincomycin and streptogramins, contained neither m6A nor m62A.

UI	MeSH Term	Description	Entries
D008745	Methylation	Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)	Methylations
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
D004917	Erythromycin	A bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Erythromycin A is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins.	Erycette,Erymax,Erythromycin A,Erythromycin C,Erythromycin Lactate,Erythromycin Phosphate,Ilotycin,T-Stat,Lactate, Erythromycin,Phosphate, Erythromycin,T Stat,TStat
D000225	Adenine	A purine base and a fundamental unit of ADENINE NUCLEOTIDES.	Vitamin B 4,4, Vitamin B,B 4, Vitamin
D000900	Anti-Bacterial Agents	Substances that inhibit the growth or reproduction of BACTERIA.	Anti-Bacterial Agent,Anti-Bacterial Compound,Anti-Mycobacterial Agent,Antibacterial Agent,Antibiotics,Antimycobacterial Agent,Bacteriocidal Agent,Bacteriocide,Anti-Bacterial Compounds,Anti-Mycobacterial Agents,Antibacterial Agents,Antibiotic,Antimycobacterial Agents,Bacteriocidal Agents,Bacteriocides,Agent, Anti-Bacterial,Agent, Anti-Mycobacterial,Agent, Antibacterial,Agent, Antimycobacterial,Agent, Bacteriocidal,Agents, Anti-Bacterial,Agents, Anti-Mycobacterial,Agents, Antibacterial,Agents, Antimycobacterial,Agents, Bacteriocidal,Anti Bacterial Agent,Anti Bacterial Agents,Anti Bacterial Compound,Anti Bacterial Compounds,Anti Mycobacterial Agent,Anti Mycobacterial Agents,Compound, Anti-Bacterial,Compounds, Anti-Bacterial
D012329	RNA, Bacterial	Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.	Bacterial RNA
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
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013302	Streptomyces	A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.
D014792	Visual Acuity	Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.	Acuities, Visual,Acuity, Visual,Visual Acuities