The cloverleaf model of tRNA is a model that depicts the molecular structure of

tRNA Transfer ribonucleic acid (tRNA), formerly referred to as soluble ribonucleic acid (sRNA), is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes). In a cell, it provides the physical link between the gene ...

. The model revealed that the chain of tRNA consists of two ends—sometimes called "business ends"—and three arms. Two of the arms have a loop, D-loop (dihydro U loop) and Tψc-loop with a

ribosome Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order s ...

recognition site. The third arm, known as the "variable arm", has a stem with optional loop. One end of the chains (with a double stranded structure in which the 5' and 3' ends are adjacent to each other), the amino acids acceptor stem, usually attaches to

amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the Proteinogenic amino acid, 22 α-amino acids incorporated into p ...

and such reactions are often catalyzed by a specific enzymes,

aminoacyl tRNA synthetase An aminoacyl-tRNA synthetase (aaRS or ARS), also called tRNA-ligase, is an enzyme that attaches the appropriate amino acid onto its corresponding tRNA. It does so by catalyzing the transesterification of a specific cognate amino acid or its pre ...

. For example, if the amino acid that attach to the end is

phenylalanine Phenylalanine (symbol Phe or F) is an essential α-amino acid with the chemical formula, formula . It can be viewed as a benzyl group substituent, substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of ...

, the reaction will be catalyzed by '' phenylalanine-tRNA synthase'' to produce tRNA^phe. The other end—the bottom often called the "DNA arm"—consists of a three base sequence that pairs with a complementary base sequence in a

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ...

References

{{DEFAULTSORT:Transfer Rna RNA Protein biosynthesis Non-coding RNA Articles containing video clips

See also

References