Quasi Periodic Primary Structure of Core Proteins of Human T-Limphotropic Leukemia Retroviruses

Fourier anal. was applied to the primary structures of 2 core proteins of human T-lymphotropic leukemia retroviruses HTLV-I and HTLV-II. The resulting autocorrelation functions display striking patterns that can be interpreted in terms of .apprx.4-fold quasi-periodicity of the primary structures. Self-alignments of the amino acid sequences contg. a few gaps are consistent with the above finding and suggest that the tertiary structure of these 2 homologous core proteins contains .alpha.-helical and .delta.-helical segments, the latter being characteristic of the 3-fold helix in collagen.