HIV-1 proteinase as structural model of intercellular transport proteins of plant viruses.
Intracellular movement of viral infections of plants requires a virus-encoded protein. Alignment of amino acid sequences of central conserved regions of such proteins produced a sequence profile that resembled that of lentiviral proteinases. The known three-dimensional structure of the proteinase encoded by the human immunodeficiency virus-1 (HIV-1) may serve as a model for the three-dimensional structure of the central region of the plant viral proteins. Secondary structures predicted for the plant viral proteins from their amino acid sequences correlate well with those predicted from a proteinase model. In addition, the positions of temperature-sensitive and resistance-breaking mutations in the intercellular transport protein of tobacco mosaic virus are consistent with a structural similarity between the plant viral proteins and the lentiviral proteinases. In a suggested model, the dimeric proteinase-similar domain serves as tether for the attachment of N- and C-terminal domains. The C-terminal domain may be an RNA-binding domain. The similarity was used to assign intercellular transport function to a previously unidentified coding region of the genomes of bacilliform DNA viruses.
Melcher
U
U
Department of Biochemistry, Oklahoma State University, Stillwater 74078-0454.
D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry*; D010450:Endopeptidases / Q000737:chemistry*; D015497:HIV-1 / Q000201:enzymology*; D008969:Molecular Sequence Data; D010942:Plant Viruses / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000737:chemistry*
D002352:Carrier Proteins; D014764:Viral Proteins; D010450:Endopeptidases