Which RNA is clover-shaped?

Which RNA is clover-shaped?

• A. mRNA
• B. tRNA
• C. rRNA
• D. siRNA

Answer: (B)

tRNA is clover-shaped because its single RNA strand folds back on itself to create four arms: the acceptor stem where the amino acid attaches, the D loop, the anticodon loop that pairs with the mRNA codon, and the TΨC loop. This cloverleaf secondary structure is stabilized by internal base pairing and is essential for tRNA’s role as the adaptor that brings the correct amino acid to the ribosome and reads the genetic code via its anticodon. In three dimensions, tRNA also adopts an L-shaped geometry that fits into the ribosome’s active site to position the amino acid for incorporation into the growing protein. Other RNAs don’t have this cloverleaf pattern: mRNA is typically linear and serves as a template, rRNA is a structural component of the ribosome, and siRNA is usually a short double-stranded molecule involved in silencing genes.

tRNA is clover-shaped because its single RNA strand folds back on itself to create four arms: the acceptor stem where the amino acid attaches, the D loop, the anticodon loop that pairs with the mRNA codon, and the TΨC loop. This cloverleaf secondary structure is stabilized by internal base pairing and is essential for tRNA’s role as the adaptor that brings the correct amino acid to the ribosome and reads the genetic code via its anticodon. In three dimensions, tRNA also adopts an L-shaped geometry that fits into the ribosome’s active site to position the amino acid for incorporation into the growing protein. Other RNAs don’t have this cloverleaf pattern: mRNA is typically linear and serves as a template, rRNA is a structural component of the ribosome, and siRNA is usually a short double-stranded molecule involved in silencing genes.