Protein Eng. 1997 May;10(5):601-6. Unique Identifier : AIDSLINE
Purified recombinant human immunodeficiency virus type 1 (HIV-1)
integrase and certain deletion mutants exhibit heterogeneity consistent
with proteolysis at a site close to the C-terminus. Electrospray
ionization mass spectrometric analysis indicated that proteolytic
cleavage generated a protein missing five residues from the C-terminus.
PCR mutagenesis of amino acids on either side of the cleavage site
identified two changes which were subsequently shown to prevent clipping
when proteins were expressed and purified from Escherichia coli: the
substitution of Arg284, the residue on the C-terminal side of the
cleavage site, by either glycine or lysine. The introduction of either
of these mutations into full-length integrase did not affect in vitro 3'
processing or strand transfer activities. Thus, the incorporation of
either of these mutations is likely to be beneficial when homogeneity of
HIV-1 integrase is a concern, as in crystallographic or nuclear magnetic
resonance spectroscopic experiments.
*HIV Integrase/METABOLISM *HIV Protease/METABOLISM