The active site region of the vitamin K-dependent carboxylase includes both the amino-terminal hydrophobic and carboxy-terminal hydrophilic domains of the protein.
In order to localize the active site of the vitamin K-dependent carboxylase, we developed an affinity probe containing the propeptide and the first two carboxylatable glutamate residues conserved in many native substrates. This probe crosslinked to both the hydrophobic amino-terminal and hydrophilic carboxy-terminal domains of the carboxylase, in contrast with previous work which localized both the catalytic and the propeptide binding site within the amino-terminal hydrophobic domain. Amino acid analysis revealed that the mass of an amino-terminal fragment is seriously underestimated by SDS-PAGE. Reanalysis of the published data in light of this information suggests that a portion of the propeptide binding site resides within the carboxy-terminal hydrophilic domain.
Maillet
M
M
Laboratoire de Chimie Organique Biologique, Université Pierre et Marie Curie, Paris, France. mmaillet@buli.uwaterloo.ca
Morris
D
D
Gaudry
M
M
Marquet
A
A
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019735:Carbon-Carbon Ligases / Q000737:chemistry*; D002417:Cattle; D005164:Factor IX / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000737:chemistry; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D010777:Photochemistry; D011485:Protein Binding; D011498:Protein Precursors / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity
D010446:Peptide Fragments; D011498:Protein Precursors; D011994:Recombinant Proteins; D005164:Factor IX; D019735:Carbon-Carbon Ligases; C020660:glutamyl carboxylase