History
Katherine Lemon and Alan Grossman showed using Bacillus subtilis that replisomes do not move like trains along a track but DNA is actually fed through a stationary pair of replisomes located at the cell membrane. In their experiment, the replisomes in B. subtilis were each tagged with green fluorescent protein, and the location of the complex was monitored in replicating cells using fluorescence microscopy. If the replisomes moved like a train on a track, the polymerase-GFP protein would be found at different positions in each cell. Instead, however, in every replicating cell, replisomes were observed as distinct fluorescent foci located at or near midcell. Cellular DNA stained with a blue fluorescent dye (DAPI) clearly occupied most of the cytoplasmic space.
Read more about this topic: Replisome
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