Figure 4.

FCK1 catalyses the formation of isopentenyladenine in vitro from adenosine monophosphate and dimethylallyl pyrophosphate. (A) The FCK1 protein was expressed in Escherichia coli as an N‐terminally histidine (His)‐tagged fusion protein. The expected size of the protein is ∼55 kDa. (B) Extracted ion chromatograms of the final expected protonated product (isopentenyladenine, iP) and intermediate (isopentenyladenine riboside monophosphate, iPRMP) of the two reactions catalysed by the bifunctional FCK1.