Functions are not so rare at all, and definitely not isolated, in sequence space of biopolymers

[Mercer (John Mercer)]

@Mercer

@Giltil

The bindings involve in complex functional proteins such as DNA polymerases or ligand-gated ion channels are not mere unspecified bindings, but highly fine tuned, integrated, coordinated and regulated bindings which can only be established within large proteins exhibiting high functional information.

If it’s that fine tuned, how was it that my colleagues and I could change the specificity of two of the most complex proteins known (myosins) without a significant effect on their normal functions, merely by changing a single amino-acid residue in the active site to one not found in nature?

If you are correct, we could not possibly have succeeded. Link to 5 papers below:

So, Gil, shall we go through these papers together?