The T-arm or T-loop is a specialized region on the
tRNA
Transfer RNA (abbreviated tRNA and formerly referred to as sRNA, for soluble RNA) is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes), that serves as the physical link between the mRNA and the amino ac ...
molecule which acts as a special recognition site for the
ribosome
Ribosomes ( ) are macromolecular machines, found within all cells, that perform biological protein synthesis (mRNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to ...
to form a tRNA-ribosome complex during
protein biosynthesis
Protein biosynthesis (or protein synthesis) is a core biological process, occurring inside cells, balancing the loss of cellular proteins (via degradation or export) through the production of new proteins. Proteins perform a number of critical ...
or
translation (biology)
In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after the process of transcription (biology), transcription of DNA to RNA in the cell's nucleus ( ...
.
The T-arm has two components to it; the T-stems and the T-loop.
* There are two T-stems of five base pairs each. T-stem 1 is from 49-53 and T-stem 2 is from 61-65.
* The T-loop is also often known as the TΨC arm due to the presence of
thymidine
Thymidine (symbol dT or dThd), also known as deoxythymidine, deoxyribosylthymine, or thymine deoxyriboside, is a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. I ...
,
pseudouridine
Pseudouridine (abbreviated by the Greek letter psi- Ψ) is an isomer of the nucleoside uridine in which the uracil is attached via a carbon-carbon instead of a nitrogen-carbon glycosidic bond. (In this configuration, uracil is sometimes referred ...
and
cytidine
Cytidine (symbol C or Cyd) is a nucleoside molecule that is formed when cytosine is attached to a ribose ring (also known as a ribofuranose) via a β-N1- glycosidic bond. Cytidine is a component of RNA. It is a white water-soluble solid. which ...
residues.
Organisms with T-loop lacking tRNA exhibit a much lower level of
aminoacylation
Aminoacylation is the process of adding an aminoacyl group to a compound.
See also
*Acylation
* tRNA aminoacylation
*Transfer RNA-like structures
Transfer RNA-like structures (tRNA-like structures) are RNA sequences, which have a similar tertiar ...
and
EF-Tu
EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome. It is a G-protein, and facilitates the selection and binding of an aa-tRNA to th ...
-binding than in organisms which have the native tRNA.
{{DEFAULTSORT:T Arm
RNA
Protein biosynthesis