Scripps VIVO scripps research logo

  • Index
  • Log in
  • Home
  • People
  • Organizations
  • Research
  • Events
Search form

Importance of factor VIIa Gla-domain residue Arg-36 for recognition of the macromolecular substrate factor X Gla-domain

Academic Article
uri icon
  • Overview
  • Identity
  • Additional Document Info
  • View All
scroll to property group menus

Overview

authors

  • Ruf, Wolfram
  • Shobe, J.
  • Rao, S. M.
  • Dickinson, C. D.
  • Olson, Arthur
  • Edgington, Thomas

publication date

  • February 1999

journal

  • Biochemistry  Journal

abstract

  • Macromolecular substrate docking with coagulation enzyme-cofactor complexes involves multiple contacts distant from the enzyme's catalytic cleft. Here we characterize the binding of the Gla-domain of macromolecular substrate coagulation factor X to the complex of tissue factor (TF) and VIIa. Site-directed mutagenesis of charged residue side chains in the VIIa Gla-domain identified Arg-36 as being important for macromolecular substrate docking. Ala substitution for Arg-36 resulted in an increased KM and a decreased rate of X activation. X with a truncated Gla-domain was activated by mutant and wild-type VIIa at indistinguishable rates, demonstrating that Arg-36 interactions require a properly folded Gla-domain of the macromolecular substrate. VIIa Arg-36 was also required for effective docking of the X Gla-domain in the absence of phospholipid, demonstrating that the Gla-domain of VIIa participates in protein-protein interactions with X. In the absence of TF, the mutant VIIa had essentially normal function, indicating that the cofactor positions VIIa's Gla-domain for optimal macromolecular substrate docking. Computational docking suggests multiple charge complementary contacts of the X Gla-domain with TF.VIIa. A prominent interaction is made by the functionally important X residue Gla-14 with the center of the extended docking site created by residues in the carboxyl module of TF and the contiguous VIIa Gla-domain. These data demonstrate the functional importance of interactions of the Gla-domains of enzyme and substrate, and begin to elucidate the molecular details of the ternary TF.VIIa.X complex.

subject areas

  • 1-Carboxyglutamic Acid
  • Arginine
  • Endopeptidases
  • Factor VIIa
  • Factor X
  • Humans
  • Hydrolysis
  • Macromolecular Substances
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Peptide Fragments
  • Phospholipids
  • Protein Binding
  • Protein Structure, Tertiary
  • Software
  • Static Electricity
  • Substrate Specificity
  • Thromboplastin
scroll to property group menus

Identity

International Standard Serial Number (ISSN)

  • 0006-2960

Digital Object Identifier (DOI)

  • 10.1021/bi982254r

PubMed ID

  • 10026279
scroll to property group menus

Additional Document Info

start page

  • 1957

end page

  • 1966

volume

  • 38

issue

  • 7

©2021 The Scripps Research Institute | Terms of Use | Powered by VIVO

  • About
  • Contact Us
  • Support