title: Precise localisation of three intra-RNA cross-links in 23S RNA and one in 5S RNA, induced by treatment of Escherichia coli 50S ribosomal subunits with bis-(2-chloroethyl)-methylamine.
abstract: Treatment of E. coli 50S ribosomal subunits with low doses of bis-(2-chloroethyl)-methylamine ("nitrogen mustard") leads to formation of a number of intra-RNA and RNA-protein cross-links. After partial digestion of the cross-linked subunits with cobra venom nuclease, followed by destruction of the protein moiety with proteinase K, complexes containing the intra-RNA cross-links were isolated by two-dimensional gel electrophoresis. The individual complexes were subjected to oligonucleotide analysis, either directly or after a second partial digestion procedure using ribonuclease T1, and the cross-link sites determined. In 23S RNA, the cross-links found were between bases 763 and 1567, 1210 and 1236, 1482 and 1501; in 5S RNA, base 69 was cross-linked to base 107. The significance of these cross-links in relation to the three-dimensional organization of the ribosomal RNA is discussed.
mesh_terms: D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism*; D008466:Mechlorethamine / Q000494:pharmacology*; D009843:Oligoribonucleotides / Q000032:analysis; D012335:RNA, Ribosomal / Q000302:isolation & purification / Q000378:metabolism*; D006163:Ribonuclease T1; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D009843:Oligoribonucleotides; D012335:RNA, Ribosomal; D008466:Mechlorethamine; D006163:Ribonuclease T1