How to flip a bit a specific bit in a human genome

David Liu's lab last week published [1] an updated version 4 of their genomic "Base Editor" that is capable of switching a C to a T with sequence specificity within a living genome. I try to break down the sequence and componentry of the genetic machine that provides the edits.

I'm trying to help demystify the mechanical nanotechnology being used in genetic engineering. In some senses they're quite simple, 5 or 6 component machines. This is one of the more 'advanced' proteins I've seen built, and it only contains 8 different kinds of components.

[1] http://advances.sciencemag.org/content/3/8/eaao4774