Conformational states of 18 S rRNA from HeLa cells detected by gel electrophoresis.

Gel electrophoretic analysis has been used to study some of the conformational properties of 18 S rRNA from HeLa cells. After isolation and treatment by heat or denaturants, the mobility of the RNA in 3% acrylamide/0.5% agarose composite gels was found to be altered; often there were two or more distinct components. Several of these forms could be interconverted by heating to 40 degrees C or by use of dimethyl sulfoxide. Although these comformers were easily distinguishable (by their electrophoretic properties), their melting profiles were very similar. Only a single electrophoretic form was detected when electrophoresis was performed at 40 degrees C. The conformational differences observed are probably derived by variations in base pairing and stacking that result when the parent form is cooled.