Open AccessX Protein of Hepatitis B Virus Resembles a Serine Protease Inhibitor
Author(s) -
Takada Shinako,
Koike Katsuro
Publication year - 1990
Publication title -
japanese journal of cancer research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 0910-5050
DOI - 10.1111/j.1349-7006.1990.tb02675.x
Subject(s) - serine protease , protease inhibitor (pharmacology) , virology , virus , protease , serine , hepatitis c virus , biology , biochemistry , enzyme , viral load , antiretroviral therapy
The × protein of hepatitis B virus (HBV) has been shown to be a trans ‐activator for viral and cellular genes. Amino acid sequences in × protein were found to be highly homologous to functionally essential sequences in the “Kunitz domain,’characteristic of Kunitz‐type serine protease inhibitors. Mutations at these sequences completely abolished trans ‐activation. Consequently, HBV × protein resembles a serine protease inhibitor or its analogue, and may bring about trans ‐activation by activating certain transcriptional factors through proteolytic cleavage alteration.