Cleavage of a 23S rRNA pseudoknot by phenanthroline-Cu(II).
Studying the intricate folding of rRNA within the ribosome remains a complex problem. Phenanthroline-Cu(II) complexes cleave phosphodiester bonds in rRNA in specific regions, apparently especially where the rRNA structure is constrained in some fashion. We have introduced phenanthroline-copper complexes into 50S Escherichia coli ribosomal subunits and shown specific cleavages in the regions containing nucleotides 60-66 and 87-100. This specificity of cleavage is reduced when the ribosome is heated to 80 degrees C and reduced to background when the ribosomal proteins are extracted and the cleavage repeated on protein-free 23S rRNA. It has been suggested that nucleotides 60-66 and 87-95 in E.coli 23S rRNA are involved in a putative pseudoknot structure, which is supported by covariance data. The paired cleavages of nearly equal intensity of these two regions, when in the ribosome, may further support the existence of a pseudoknot structure in the 100 region of 23S rRNA.
Muth
G W
GW
Department of Chemistry, The University of Montana, Missoula, MT 59812, USA.
Thompson
C M
CM
Hill
W E
WE
D001665:Binding Sites; D003300:Copper; D007364:Intercalating Agents / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D010618:Phenanthrolines / Q000737:chemistry / Q000378:metabolism*; D012338:RNA, Ribosomal, 23S / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes
C119292:5-acetylamino-1,10-phenanthroline; D007364:Intercalating Agents; C119293:N-acetyl-2-aminomethyl-1,10-phenanthroline; D010618:Phenanthrolines; D012338:RNA, Ribosomal, 23S; D003300:Copper; C025205:1,10-phenanthroline