Calcium-binding analysis and molecular modeling reveal echis coagulation factor IX/factor X-binding protein has the Ca-binding properties and Ca ion-independent folding of other C-type lectin-like proteins.
Many biologically active heterodimeric proteins of snake venom consist of two C-type lectin-like subunits. One of these proteins, habu IX/X-bp, is a Gla domain-binding protein whose subunits both bind to a Ca2+ ion, with a total of two Ca2+-binding sites. The molecular modeling and Ca2+-binding analysis of echis IX/X-bp revealed that it lacks one of two Ca2+-binding sites, though the folding of this subunit is conserved. It is concluded that heterodimeric C-type lectin-like proteins function independent of Ca2+ and have essentially a similar folding to habu IX/X-bp.
Atoda
Hideko
H
Department of Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, Japan.
Kaneko
Hiroki
H
Mizuno
Hiroshi
H
Morita
Takashi
T
D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D037181:Lectins, C-Type / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D017386:Sequence Homology, Amino Acid; D014757:Viper Venoms / Q000737:chemistry*
D037181:Lectins, C-Type; D021122:Protein Subunits; D014757:Viper Venoms; C099136:factor IX-factor X-binding protein, Echis carinatus; D002118:Calcium