Further evidence for the relationship of HIV-1 gp120 V3 loops with Ig superfamily members: similarity with the putative CDR3 region of T-cell receptor delta-chains.
Twenty-five V3 loops of envelope gp 120 extracted from 30 HIV-1 isolates were compared with T-cell receptor (TCR) subunits variable (V) portions using pairwise alignments of 11-residue peptides. The results indicate that, in comparison with random sequences, the analyzed V3 loops, unlike control (unrelated) sequences, display highly significant local similarity with TCR V delta (p approximately 10(-20)). However, pattern-matching searches were performed on a much larger number of V3 loops (484). In particular, selective pattern TR * * * NT * K * I is shared by V delta from human T-cell line KT19E and 230 HIV-1 V3 loops (N-terminal portion). Pattern RA * YT * * * I * G is common for V delta chain isolated from T-cell line DS6 of an immunodeficient patient and 69 V3 loops (C-terminal portion). The presented delta-chain portions of sequence similarity with the V3 loops overlap the putative complementarity-determining region (CDR3), thus possibly indicating functional similarity too.
Laboratory for Multidisciplinary Research, Institute for Nuclear Sciences Vinca, Belgrade, Yugoslavia.
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Metlas
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Skerl
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Veljković
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Pongor
D000595:Amino Acid Sequence; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000737:chemistry*; D008285:Major Histocompatibility Complex / Q000276:immunology; D008969:Molecular Sequence Data; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000737:chemistry* / Q000276:immunology*; D017386:Sequence Homology, Amino Acid
D015699:HIV Envelope Protein gp120; D007135:Immunoglobulin Variable Region; D016692:Receptors, Antigen, T-Cell, gamma-delta