Studies with mutated forms of tyrosyl-tRNA synthetase showed that changing some active-site amino acids decreased the enzyme's turnover number but not the Km of the reaction. What is the best interpretation of these results?

 

The best interpretation of the results is that the;

•  Reaction's Km does not depend on which amino acid side chains are found in the active site. 
• Amino acids involved with the transition-state complex are different from the ones that affect enzyme-substrate association. 
• Two substrates, tyrosine and ATP, must enter the active site in a specific order.
•  Transition state for this reaction is formed prior to the formation of the ES complex.
•  Two terms, Km and turnover number, are inversely proportional