t-RNA-The actual structure of tRNA looks like a clover leaf having four arms/loops viz: the acceptor arm, ribosomal binding arm, anticodon loop and DHU arm. This clover leaf model of tRNA was proposed by Robert Holley in 1968.
According to Kim (1973) the adapter molecule looks like an L-shaped structure. This is 3-dimensional and is known as the L-shaped model of tRNA.
