Different conformational forms of Escherichia coli and rat liver 5S rRNA revealed by Pb(II)-induced hydrolysis.
Different stable forms of Escherichia coli and rat liver 5S rRNA have been probed by Pb(II)-induced hydrolysis. In the native A forms of 5S rRNA, Pb2+ reveal single-stranded RNA stretches and regions of increased conformational flexibility or distorted by the presence of bulged nucleotides. Hydrolysis of urea/EDTA-treated E. coli 5S rRNA (B form) shows the presence of two strong helical domains; helix A retained from the A form and a helix composed of RNA regions G33-C42 and G79-C88. Other RNA regions resistant to hydrolysis may be involved in alternative base pairing, causing conformational heterogeneity of that form. Pb(II)-induced hydrolysis distinguishes two different forms of rat liver 5S rRNA; the native A form and the form obtained by renaturation of 5S rRNA in the presence of EDTA. Pb(II)-hydrolysis data suggest that both forms are highly structured. In the latter form, the orientation of the bulged C66 is changed with respect to helix B. At the same time, a new helical segment is possibly formed, composed of nucleotides from helix C and loop c on one side and from helix E and loop d' on the other.
Ciesiołlka
J
J
Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań.
Lorenz
S
S
Erdmann
V A
VA
D000818:Animals; D001483:Base Sequence; D002413:Cations, Divalent; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism*; D006868:Hydrolysis; D007854:Lead / Q000378:metabolism*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012341:RNA, Ribosomal, 5S / Q000235:genetics / Q000378:metabolism*; D051381:Rats
D002413:Cations, Divalent; D012341:RNA, Ribosomal, 5S; D007854:Lead