The human T-cell lymphotropic virus type-I dimerization initiation site forms a hairpin loop, unlike previously characterized retroviral dimerization motifs

The structural motif responsible for HTLV-I RNA dimerization forms a trinucleotide RNA loop, and is not like previously characterized retroviral dimerization motif. This is formed by an unusual C:synG base pair closing the loop, and indicates that such a motif also exist in other deltaretroviruses.