MOLECULAR MODELING OF THE STERIC STRUCTURE OF THE ENVELOPE F1 ANTIGEN OF YERSINIA-PESTIS

Steric structure of the envelope F1 protein of Yersinia pestis was reconstructed by computer modeling taking into account structural similarities between F1 and interleukins (IL)-1 alpha, -beta, -ra and by using the known atomic coordinates for huIL-1 beta obtained by the X-ray crystallography. Of 18 hydrophobic positions forming a hydrophobic core in all the proteins studied with the IL-1-like conformation, 15 positions are occupied by hydrophobic residues in F1 protein as well. Of 8 homologous positions occupied by the amino acid residues of similar charge in all huIL-1 alpha, -beta, -ra, 5 positions are conserved in F1 antigen. The B-cell epitope accessible to antibodies in polymeric F1 is exposed as an hydrophilic loop at the surface opposite to the C-terminal sequence, forming a conserved binding site with periplasmic molecular chaperones.