1v1o
STAPHYLOCOCCAL SUPERANTIGEN-LIKE PROTEIN 7
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OverviewOverview
The staphylococcal superantigen-like proteins (SSLs) are a family of, polymorphic paralogs encoded in the Staphylococcus aureus genome whose, function is unknown. The crystal structure of SSL7 was determined and, compared to that of SSL5 and that of a classical superantigen, streptococcal pyrogenic exotoxin. Although the overall architecture of the, superantigen family is retained in both SSL7 and SSL5, there are, significant differences in the structures which suggest that the, characteristic major histocompatibility complex binding site of, superantigens has been lost. To complement these data, the abilities of, SSL7 and a closely related paralog, SSL9, to interact with cells of the, immune system were investigated. In populations of human white blood, cells, both SSLs interacted selectively with monocytes via specific, saturable but separate binding sites, which led to rapid uptake of the, SSLs. In addition, SSLs were rapidly taken up by dendritic cells, but not, by macrophages, into the same endosomal compartment as dextran. The, ability of these secreted proteins to target antigen-presenting cells may, enhance a misplaced antibody response against the proteins, which may, facilitate bacterial colonization rather than contribute to host, protection. Like classical superantigens, therefore, SSLs may distract the, host's immune system, but they may do so via entirely different molecular, mechanisms.
About this StructureAbout this Structure
1V1O is a Single protein structure of sequence from Staphylococcus aureus. Full crystallographic information is available from OCA.
ReferenceReference
Structural relationships and cellular tropism of staphylococcal superantigen-like proteins., Al-Shangiti AM, Naylor CE, Nair SP, Briggs DC, Henderson B, Chain BM, Infect Immun. 2004 Jul;72(7):4261-70. PMID:15213171
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