|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
2 Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, Florida 33101, USA
3 Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
(RECEIVED April 20, 2004; FINAL REVISION May 24, 2004; ACCEPTED May 24, 2004)
Streptococcal pyrogenic exotoxin A (SpeA1) is a bacterial superantigen associated with scarlet fever and streptococcal toxic shock syndrome (STSS). SpeA1 is found in both monomeric and dimeric forms, and previous work suggested that the dimer results from an intermolecular disulfide bond between the cysteines at positions 90 of each monomer. Here, we present the crystal structure of the dimeric form of SpeA1. The toxin crystallizes in the orthorhombic space group P212121, with two dimers in the crystallographic asymmetric unit. The final structure has a crystallographic R-factor of 21.52% for 7248 protein atoms, 136 water molecules, and 4 zinc atoms (one zinc atom per molecule). The implications of SpeA1 dimer on MHC class II and T-cell receptor recognition are discussed.
Keywords: X-ray crystallography; superantigen; streptococcal pyrogenic exotoxin A1; T-cell receptor; MHC class II molecule
Reprint requests to: K. Ravi Acharya, Department of Biology and Biochemistry, Building 4 South, University of Bath, Claverton Down, Bath BA2 7AY, UK; e-mail: K.R.Acharya{at}bath.ac.uk, fax: +44-1225-386779.
Article published online ahead of print. Article and publication date are at http://www.proteinscience.org/cgi/doi/10.1110/ps.04826804.
![]()
CiteULike
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |