Essentials of Genetics 9th Edition by Michael Palladino William Klug, Michael Cummings, Charlotte Spencer

Exercise 14

A glycine residue exists at position 210 of the tryptophan synthetase enzyme of wild-type E. coli. If the codon specifying glycine is GGA, how many single-base substitutions will result in an amino acid substitution at position 210, and what are they? How many will result if the wild-type codon is GGU?