Based on our understanding of protein structure and function

Based on our understanding of protein structure and function, how would the crystal structure from the enzyme alone differ from that bound to substrate analog? What important info can we obtain from comparing these two protein structures?

Solution

According to lock and key model, enzymes are flexible and change their structures while binding to Substrates. The crystal structure of enzyme alone not give information about enzyme active site and the active site associated amino acids. Where as Substrate bound enzyme structure can give information about active site, Amino acids involved in acctual catalysis and type of interactions exist between enzyme and substrate