Structural studies of a novel cluster of superantigen-like proteins from Staphylococcus aureus
The SET proteins (now known as SSL proteins) were discovered by our collaborators (Williams et al.) at the Eastman Dental Institute in London, UK. This group of proteins all share
the "staphylococcal superantigen motif", and share in the order of 25% sequence homology
with the other, established supoerantigens.
We have now solved several structures of SSL7 (formerly SET-1). This follows the structure determination of SET-3 by Arcus et al.
Both SSL7 and SET-3 look like superantigens, with an rmsd between
SSL7 and SPE-C (its closest homologue) of around 1.5 angstoms.
We are currently engaged in efforts to discover the true function of
these proteins, which seem to have some sort of immuno-modulatory
effect. This immunology work is being carried out in collaboration with
the Anthony Nolan Research Institute, Royal Free Hospital, London.
X-ray structure of SSL7 dimer
(unpublished work)
REFERENCES
Al-Shangiti, A.M.*, Naylor, C.E.*, Nair, S.P., Briggs, D.C., Henderson, B. and Chain, B.M. Structural relationships and cellular tropism of staphylococcal superantigen like proteins. Infect. Immun. 72, 4261-70 (2004).*These authors contributed equally to the work.
Arcus, V. L., Langley, R., Proft, T., Fraser, J. D., Baker, E. N.: The
Three-Dimensional Structure of a Superantigen-Like Protein, Set3, from
a Pathogenicity Island of the Staphylococcus Aureus Genome J.Biol.Chem.277 pp. 32274 (2002)
Williams R.J., Ward J.M., Henderson B., Poole S., O'Hara B.P., Wilson
M., Nair S.P. "Identification of a novel gene cluster encoding
staphylococcal exotoxin-like proteins: characterization of the
prototypic gene and its protein product, SET1." Infect. Immun.68:4407-4415(2000).
