#Id: 7074
#Unit 3. Fundamental Processes
Valyl-tRNA synthetase can sterically exclude isoleucine from its catalytic pocket because isoleucine is larger than valine. In contrast, valine should slip easily into the catalytic pocket of the isoleucyl-tRNA synthetase. Although both amino acids will fit into the isoleucyl-tRNA synthetase amino acid–binding site, interactions with the extra bonding with tyrosine’s OH group. Since no other amino acid resembles tyrosine, the enzyme can do without an editing function
