Question

What is the significance of the variable loop in the cloverleaf model of tRNA?

Options

• Contains the anticodon for all tRNAs

• Binds aminoacyl-tRNA synthetase exclusively

• Directly involved in ribosomal binding only

• Variable in size and helps in structural identity

Answer 1

The variable loop, also called the extra arm, varies significantly in size among different tRNAs (ranging from 4 to 21 nucleotides). This structural variation contributes to the unique three-dimensional identity of each tRNA, allowing aminoacyl-tRNA synthetases to discriminate between different tRNAs and ensure accurate aminoacylation.