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

• Published in: The Journal of biological chemistry Vol. 263; no. 10; pp. 4939 - 4944
• Main Authors: Montesano, L, Glitz, D G
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 05.04.1988; American Society for Biochemistry and Molecular Biology
• Subjects: Adenosine - analogs & derivatives; Adenosine - analysis; Antibodies; Antigen-Antibody Complex - analysis; Biological and medical sciences; Cell structures and functions; Cytoplasm - ultrastructure; Fundamental and applied biological sciences. Psychology; Guanosine - analogs & derivatives; Guanosine - analysis; Immunoassay; Microscopy, Electron; Molecular and cellular biology; Plants - ultrastructure; Ribosome; Ribosomes - ultrastructure; RNA, Ribosomal - analysis; Triticum - ultrastructure; Transmission electron microscopy; Ribosome; Nucleotide sequence; Antibody; Wheat germ; 40S»-Ribosome; Localization; 18S-RNA; Structure; Cytoplasm
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)68877-5

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.