The 3′‐orf protein of human immunodeficiency virus shows structural homology with the phosphorylation domain of human interleukin‐2 receptor and the ATP‐binding site of the protein kinase family

Abstract
The primary amino acid sequence within a stretch of 25 residues (positions 91–116) of the middle portion of the 3-′orf protein (p273′-orf) of the human immunodeficiency virus (HIV) shares structural homology with a highly charged region within the intracytoplasmic phosphorylation domain of human interleukin-2 receptor (IL-2R) and the ATP-binding site of the catalytic subunit of cAMP-dependent protein kinase (cAMP-PK) and other members of the protein kinase family. Comparison of the predicted secondary structure within this region of p273′-orf with the phosphorylation domain of human IL-2R and the ATP-binding region of the phospho-kinase family of protein suggests that the 3′-orf protein could serve homologous function(s).