Biomaterial Database

Wheat germ cytoplasmic ribosomes. Localization of 7-methylguanosine and 6-methyladenosine by electron microscopy of immune complexes. 1988

L Montesano, and D G Glitz

Department of Biological Chemistry, School of Medicine, University of California, Los Angeles 90024.

Nucleoside analysis of the RNA from the small subunit of wheat germ cytoplasmic ribosomes shows 1 mol each of N7-methylguanosine and N6-methyladenosine/mol of RNA. Antibodies directed against each methylated nucleoside were used to localize these residues within the subunit by electron microscopy of immune complexes. Antibodies to 7-methylguanosine bound 40 S subunits at a single site, at or slightly above the division between the upper and lower segments of the particle and on the surface furthest from the platform (or large lobe) of the subunit. This site is essentially equivalent to that previously seen with Escherichia coli and chloroplast 30 S subunits (Trempe, M. R., Ohgi, K., and Glitz, D. G. (1982) J. Biol. Chem. 257, 9822-9829). Antibodies to N6-monomethyladenosine were induced in rabbits with a nucleoside-albumin conjugate and shown to be specific for the modified nucleoside. Electron microscopy of antibody-subunit complexes placed the methyladenosine residue in a position that is essentially indistinguishable from that of 7-methylguanosine.

UI	MeSH Term	Description	Entries
D007118	Immunoassay	A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.	Immunochromatographic Assay,Assay, Immunochromatographic,Assays, Immunochromatographic,Immunoassays,Immunochromatographic Assays
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms
D006151	Guanosine	A purine nucleoside that has guanine linked by its N9 nitrogen to the C1 carbon of ribose. It is a component of ribonucleic acid and its nucleotides play important roles in metabolism. (From Dorland, 28th ed)
D000241	Adenosine	A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.	Adenocard,Adenoscan
D000906	Antibodies	Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
D000936	Antigen-Antibody Complex	The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.	Immune Complex,Antigen-Antibody Complexes,Immune Complexes,Antigen Antibody Complex,Antigen Antibody Complexes,Complex, Antigen-Antibody,Complex, Immune,Complexes, Antigen-Antibody,Complexes, Immune
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
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