Biomaterial Database

A nuclear mutation conferring thiostrepton resistance in Chlamydomonas reinhardtii affects a chloroplast ribosomal protein related to Escherichia coli ribosomal protein L11. 1993

K B McElwain, and J E Boynton, and N W Gillham

Department of Zoology, Duke University, Durham, NC 27708-0325.

We have isolated a nuclear mutant (tsp-1) of Chlamydomonas reinhardtii which is resistant to thiostrepton, an antibiotic that blocks bacterial protein synthesis. The tsp-1 mutant grows slowly in the presence or absence of thiostrepton, and its chloroplast ribosomes, although resistant to the drug, are less active than chloroplast ribosomes from the wild type. Chloroplast ribosomal protein L-23 was not detected on stained gels or immunoblots of total large subunit proteins from tsp-1 probed with antibody to the wild-type L-23 protein from C. reinhardtii. Immunoprecipitation of proteins from pulse-labeled cells showed that tsp-1 synthesizes small amounts of L-23 and that the mutant protein is stable during a 90 min chase. Therefore the tsp-1 phenotype is best explained by assuming that the mutant protein synthesized is unable to assemble into the large subunit of the chloroplast ribosome and hence is degraded over time. L-23 antibodies cross-react with Escherichia coli r-protein L11, which is known to be a component of the GTPase center of the 50S ribosomal subunit. Thiostrepton-resistant mutants of Bacillus megaterium and B. subtilis lack L11, show reduced ribosome activity, and have slow growth rates. Similarities between the thiostrepton-resistant mutants of bacteria and C. reinhardtii and the immunological relatedness of Chlamydomonas L-23 to E. coli L11 suggest that L-23 is functionally homologous to the bacterial r-protein L11.

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
D011233	Precipitin Tests	Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.	Precipitin Test,Test, Precipitin,Tests, Precipitin
D002736	Chloroplasts	Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.	Chloroplast,Etioplasts,Etioplast
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012269	Ribosomal Proteins	Proteins found in ribosomes. They are believed to have a catalytic function in reconstituting biologically active ribosomal subunits.	Proteins, Ribosomal,Ribosomal Protein,Protein, Ribosomal
D012270	Ribosomes	Multicomponent ribonucleoprotein structures found in the CYTOPLASM of all cells, and in MITOCHONDRIA, and PLASTIDS. They function in PROTEIN BIOSYNTHESIS via GENETIC TRANSLATION.	Ribosome
D013883	Thiostrepton	One of the CYCLIC PEPTIDES from Streptomyces that is active against gram-positive bacteria. In veterinary medicine, it has been used in mastitis caused by gram-negative organisms and in dermatologic disorders.	Bryamycin,Gargon,Thiactin
D015153	Blotting, Western	Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.	Immunoblotting, Western,Western Blotting,Western Immunoblotting,Blot, Western,Immunoblot, Western,Western Blot,Western Immunoblot,Blots, Western,Blottings, Western,Immunoblots, Western,Immunoblottings, Western,Western Blots,Western Blottings,Western Immunoblots,Western Immunoblottings
D015180	Electrophoresis, Gel, Two-Dimensional	Electrophoresis in which a second perpendicular electrophoretic transport is performed on the separate components resulting from the first electrophoresis. This technique is usually performed on polyacrylamide gels.	Gel Electrophoresis, Two-Dimensional,Polyacrylamide Gel Electrophoresis, Two-Dimensional,2-D Gel Electrophoresis,2-D Polyacrylamide Gel Electrophoresis,2D Gel Electrophoresis,2D PAGE,2D Polyacrylamide Gel Electrophoresis,Electrophoresis, Gel, 2-D,Electrophoresis, Gel, 2D,Electrophoresis, Gel, Two Dimensional,Polyacrylamide Gel Electrophoresis, 2-D,Polyacrylamide Gel Electrophoresis, 2D,Two Dimensional Gel Electrophoresis,2 D Gel Electrophoresis,2 D Polyacrylamide Gel Electrophoresis,Electrophoresis, 2-D Gel,Electrophoresis, 2D Gel,Electrophoresis, Two-Dimensional Gel,Gel Electrophoresis, 2-D,Gel Electrophoresis, 2D,Gel Electrophoresis, Two Dimensional,PAGE, 2D,Polyacrylamide Gel Electrophoresis, 2 D,Polyacrylamide Gel Electrophoresis, Two Dimensional,Two-Dimensional Gel Electrophoresis
D016825	Chlamydomonas reinhardtii	A species of GREEN ALGAE. Delicate, hairlike appendages arise from the flagellar surface in these organisms.	Chlamydomonas reinhardii,Chlamydomonas reinhardius,Chlamydomonas reinhardtius,reinhardius, Chlamydomonas,reinhardtii, Chlamydomonas