2OTO: N-terminal Fragment Of Streptococcus Pyogenes M1 Protein

Antigenically variable M proteins are major virulence factors and immunogens of the human pathogen group A Streptococcus (GAS). Here, we report the approximately 3 angstrom resolution structure of a GAS M1 fragment containing the regions responsible for eliciting type-specific, protective immunity and for binding fibrinogen, which promotes M1 proinflammatory and antiphagocytic functions. The structure revealed substantial irregularities and instabilities throughout the coiled coil of the M1 fragment. Similar structural irregularities occur in myosin and tropomyosin, explaining the patterns of cross-reactivity seen in autoimmune sequelae of GAS infection. Sequence idealization of a large segment of the M1 coiled coil enhanced stability but diminished fibrinogen binding, proinflammatory effects, and antibody cross-reactivity, whereas it left protective immunogenicity undiminished. Idealized M proteins appear to have promise as vaccine immunogens.
PDB ID: 2OTODownload
MMDB ID: 63050
PDB Deposition Date: 2007/2/8
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 3.04  Å
Source Organism:
Similar Structures:
Biological Unit for 2OTO: dimeric; determined by author and by software (PISA)
Molecular Components in 2OTO
Label Count Molecule
Proteins (2 molecules)
M Protein
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB