Plasmin(Ogen)-Binding Alpha-Enolase from Streptococcus Pneumoniae: Crystal Structure and Evaluation of Plasmin(Ogen)-Binding Sites
Ehinger, S., Schubert, W.-D., Bergmann, S., Hammerschmidt, S., Heinz, D.W.(2004) J Mol Biol 343: 997
- PubMed: 15476816 
- DOI: https://doi.org/10.1016/j.jmb.2004.08.088
- Primary Citation of Related Structures:  
1W6T - PubMed Abstract: 
Alpha-enolases are ubiquitous cytoplasmic, glycolytic enzymes. In pathogenic bacteria, alpha-enolase doubles as a surface-displayed plasmin(ogen)-binder supporting virulence. The plasmin(ogen)-binding site was initially traced to the two C-terminal lysine residues. More recently, an internal nine-amino acid motif comprising residues 248 to 256 was identified with this function. We report the crystal structure of alpha-enolase from Streptococcus pneumoniae at 2.0A resolution, the first structure both of a plasminogen-binding and of an octameric alpha-enolase. While the dimer is structurally similar to other alpha-enolases, the octamer places the C-terminal lysine residues in an inaccessible, inter-dimer groove restricting the C-terminal lysine residues to a role in folding and oligomerization. The nine residue plasminogen-binding motif, by contrast, is exposed on the octamer surface revealing this as the primary site of interaction between alpha-enolase and plasminogen.
Organizational Affiliation: 
Division of Structural Biology, GBF-German Research Center for Biotechnology, Mascheroder Weg 1, 38124 Braunschweig, Germany.