William H. McClain
Halvorson Professor of bacteriology and molecular biology. McClain is known for the dissection of RNA-protein recognition primarily through genetic and biochemical means in bacteria. His has studied the conversion precursor tRNAs to mature tRNA, the addition of the 3'-CCAOH amino acid accepting end, the computer-assisted identification followed by an experimental verification of the sites in tRNA that determine amino acid acceptance, a process that proceeds with error rates less than one in ten thousand. His most recent work focuses on the origin of the genetic code, which is the dictionary for making protein sequences. Arising once on Earth, the genetic code is common to all life forms. Its simplicity makes it alluring to think that similar coding systems will exist beyond Earth.