Two recent events prompt me to post this (double) Talmudic Question(s). First, I had a lot of thoughts inspired by Christoph's Monday post on stop codons being recognized by charged tRNAs in a trypanosomatid: "Stops making sense." How bizarre can non-canonical codes get? Second, I was reading posts from the past.
With the code already in mind, I was immediately struck when I landed on this gem from 2008 by the late Charley Yanofksy. (Full disclosure, Charley was my post-doctoral mentor more than forty years ago, so I may be biased.) In his post, he poses several questions related to tRNA and tRNA synthetases. Fifteen years ago, Charley felt that although the genetic code was well-established, "a very exciting unsolved problem is discovering how codons were related to amino acids in the evolution of protein synthesis." Following this statement, he posed several well-defined questions. These are my favorite two:
How did a tRNA and a tRNA synthetase first evolve, and what was their ancestral source?
How were the genes for the first tRNA and tRNA synthetase duplicated and how was their specificity varied?
His questions had a Talmudic feeling back then; I think they still do! What answers come to mind?