... to be conformations that diminish it. These have not yet been examined, but it is possible that they account for some of the single-stranded nucleotides of low to intermediate reactivity. Another factor that influences nucleotide reactivity is the identity of the base: purines are approximately 1.5-fold more...

... to reduce the Fe–S clusters of the complex although it exhibits a low affinity for the enzyme. To examine whether both nucleotides induce conformational changes, we used electron microscopy to determine the overall conformation of the complex as isolated, after reduction with NADH, and after reduction...