When the great chemist Linus Pauling guessed at the DNA molecular structure he envisioned the bases to be pointing outward rather than being neatly stacked within the double helix as we know them to be. One virtue of Pauling's design is that the information-bearing bases are easily accessible. As it is, the DNA molecule must be unwound and the two strands separated when a gene is transcribed. And even before this happens the protein machines, that do the unwinding and other functions, need to determine where to go on the long DNA double helix. They do so very quickly, but how?
The protein machines that work on the DNA molecule find their starting location quickly. This means they must not be searching randomly within the cell, but instead must be intelligently moving along the DNA.
But do they actually spiral around the DNA in the grooves of the double helix molecule? New research indicates that they do, even though such a spiraling action has considerably more resistance than a non rotating motion would have. This means the the rate at which these proteins slide along the DNA is quite sensitive to the protein size, and therefore controllable by adjusting the protein size.
