WILL WONDERS NEVER CEASE?

MY VALENTINE

Will wonders never cease?

https://www.economist.com/science-and-technology/2019/01/19/adding-new-dna-letters-make-novel-proteins-possible

These people in white coats almost scare me sometimes.  Like now.

You know how we work, right?  Our  blueprint, called the DNA molecule, is nothing more than a long string of organic molecules of a sort called nucleic acids.  Although I guess lots of different configurations of nucleic acid is possible, nature uses only four, with unfamiliar names universally abbreviated a, c, g, and t.  These things are arranged like rungs on a twisted ladder – the famous double helix – with a paring with t, and of course g with c.  If the body needs some proteins for any purpose, a segment of DNA (a “gene”) is transcribed onto another molecule, much like DNA, called RNA.  This messenger RNA then is processed by an incredibly complicated organic molecule called a ribosome.  The ribosome “reads” the RNA in groups of three (a “codon”) and thus is directed to attach another complicated organic molecule (an amino acid) to a growing chain if amino acids (a polypeptide chain) which constitutes a protein.  Proteins do everything worth doing inside us, and even some things that are not worth doing.

But you knew all that.

With only four nucleic acids, and codons of three “letters”, 64 amino acids should be possible, but because of duplications and other matters only 20 actually are manufactured.  Now, however, some smart people at UC, La Jolla, have fabricated two new nucleic acids – they call them X and Y – and, moreover, succeeded in inserting them into the DNA of the bacterium E. coli.   This should give a total of 216 possible codon combinations, and Heaven knows how many new amino acids.  So, stick X and Y in the genetic code, and out must pop proteins never before seen slithering about!  Old fossil that I am, that sort of scares me.

To their credit, these La Jolla people have put their work to use in improving the usefulness of the famous immunotherapeutic drug Interleukin 2.  Good for them.  They have started a spin-off company to handle this aspect of their work.  May they make lots of money.