Abstract
Toxoplasma gondii is a persistent protozoan parasite capable of infecting almost any warm-blooded vertebrate. The surface of Toxoplasma is coated with a family of developmentally regulated glycosylphosphatidylinositol (GPI)-linked proteins (SRSs), of which SAG1 is the prototypic member. SRS proteins mediate attachment to host cells and interface with the host immune response to regulate the virulence of the parasite. The 1.7 Å structure of the immunodominant SAG1 antigen reveals a homodimeric configuration in which the dimeric interface is mediated by an extended β-sheet that forms a deep groove lined with positively charged amino acids. This basic groove seems to be conserved among SRS proteins and potentially serves as a sulfated proteoglycan-binding site on target cell surfaces, thus rationalizing the promiscuous attachment properties of Toxoplasma to a broad range of host cell types.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 606-611 |
| Number of pages | 6 |
| Journal | Nature Structural Biology |
| Volume | 9 |
| Issue number | 8 |
| DOIs | |
| State | Published - 2002 |
Funding
The authors gratefully acknowledge M. Martick, D. Chow and D. Alexander for their assistance, G. McDermott for help with MAD data collection and L. Kasper for helpful discussions. This work was funded by the NIH (K.C.G. and J.C.B.), Rita Allen Foundation (K.C.G.), American Heart Association (K.C.G.), RWJ-PRI (K.C.G.) and the California County of Alameda District Attorney’s Office (J.C.B.).
ASJC Scopus subject areas
- Genetics
- Structural Biology
- Biochemistry