According to a recent post at TheScientist.com, scientists have recently created an artificial system in which a bizarre, created ribosome reads codons in mRNA that are four bases long. You read the correctly . . . instead of reading bases three at a time (like in real life), these little monsters can read a whole different form of genetic language—or genetish, as author Matt Ridley calls it.
This breakthrough allows scientists to build a whole new system of creating proteins—one in which there could be up to 256 different possible amino acids available. This means that instead of being limited to using only the 22 naturally-occurring amino acids currently available for playing around to produce crazy new proteins, scientists can now also use synthetically modified amino acids with a variety of chemical properties. Modified or synthetic amino acids have no 3-base codons to represent them in natural genetish.
Just a few months ago, we were lauding the Nobel laureates who helped us figure out the structure of the ribosome. Now we're seeing the creation of artificial ribosomes that translate artificial genetish. I guess this is a huge breakthrough for chemists hoping to synthesize new types of proteins. It may also provide opportunities for synthetic biologists (scientists attempting to create artificial cells, tissues, and organisms). It certainly is a great starting point for a sci-fi novel!
Want to know more?
Genetic coding revamp
TheScientist.com 14 Feb 2010
[Summary of development of a new genetic language.]
Some background from the primary literature:
A chemical toolkit for proteins — an expanded genetic code
Jianming Xie et al.
Nature Reviews Molecular Cell Biology 7, 775-782 (October 2006) doi:10.1038/nrm2005
An evolved ribosome for genetic code expansion
Caroline Köhrer et al.
Nature Biotechnology 25, 745 - 746 (2007) doi:10.1038/nbt0707-745
A network of orthogonal ribosome·mRNA pairs
Oliver Rackham et al.
Nature Chemical Biology 1, 159 - 166 (2005) doi:10.1038/nchembio719