Vitamin K-Dependent Carboxylase: Possible Role of the Substrate ``Propeptide'' as an Intracellular Recognition Site
Abstract
The liver microsomal vitamin K-dependent carboxylase catalyzes the posttranslational conversion of specific glutamate residues to gamma-carboxyglutamate residues in a limited number of proteins. A number of these proteins have been shown to contain a homologous basic amino acid-rich "propeptide" between the leader sequence and the amino terminus of the mature protein. Plasmids encoding protein C, a vitamin K-dependent protein, containing or lacking a propeptide region were constructed and the protein was expressed in Escherichia coli. The protein products were assayed as substrates in an in vitro vitamin K-dependent carboxylase system. Only proteins containing a propeptide region were substrates for the enzyme. These data support the hypothesis that this sequence of the primary gene product is an important recognition site for this processing enzyme.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- February 1987
- DOI:
- 10.1073/pnas.84.3.634
- Bibcode:
- 1987PNAS...84..634S