An aminoacyl-tRNA synthetase is the enzyme that catalyzes the attachment of a particular amino acid to its corresponding tRNA.This reaction requires energy from ATP.The enzyme initially binds the amino acid and ATP,but it is unable to bind the tRNA at this point.Which of the following would be a likely next step in the reaction by which the enzyme ultimately binds the tRNA and attaches the amino acid?
A)Transfer of the ATP to the tRNA opens the active site,which allows the tRNA to bind.
B)Hydrolysis of ATP activates the amino acid,which is released,opening up the active site to allow binding of the tRNA,followed by binding of a new amino acid.
C)Hydrolysis of ATP phosphorylates the amino acid,which results in a conformational change in the active site that allows the tRNA to bind.
D)Alteration in the conformation of the tRNA allows it to bind to the active site along with the amino acid and ATP.

Question

Quizplus · Accepted Answer

Hydrolysis of ATP phosphorylates the amino acid, resulting in a conformational change in the active site of the aminoacyl-tRNA synthetase. This new conformation of the active site allows the tRNA to bind and be attached to the amino acid.

An Aminoacyl-TRNA Synthetase Is the Enzyme That Catalyzes the Attachment