The T-arm or T-loop is a specialized region on the tRNA molecule which acts as a special recognition site for the ribosome to allow a tRNA-ribosome complex to form during the process of protein biosynthesis.
The T-arm has two components to it; the T-stems and the T-loop.
Organisms with T-loop lacking tRNA exhibit a much lower level of aminoacylation and EF-Tu-binding than in organisms which have the native tRNA.
In Mammalian DNA, telomeric repeat-binding factor 2 or TRF2 has been found to remodel linear telomeric DNA into large T-loops.