So let's see exactly what we mean by an intramolecular rearrangement reaction that is catalyzed by this mutase. And let's begin with this l isomer of methylmalcouncilma that we formed in step number two. So this is our molecule. So this is carbon number one, carbon number two, and carbon number three. And the ultimate goal is to take this entire group that is shown in blue and to move it from carbon number two onto this carbon that is part of this methyl group. Now, how exactly is this reaction actually catalyzed?