3k55

Publication Abstract from PubMed

The 3.35 A resolution crystal structure of a mutant form of the staphylococcal sphingomyelinase beta toxin in which a conserved hydrophobic beta-hairpin has been deleted is reported. It is shown that this mutation induces domain swapping of a C-terminal beta-strand, leading to the formation of dimers linked by a conformationally flexible hinge region. Eight dimers are seen in the asymmetric unit, exhibiting a broad spectrum of conformations trapped in place by intermolecular contacts within the crystal lattice. Furthermore, the 16 monomers within each asymmetric unit exhibit a remarkable heterogeneity in thermal factors, which can be accounted for by the varying degrees to which each monomer interacts with other molecules in the crystal. This structure provides a unique example of the challenges associated with crystallographic study of flexible proteins.

Structure of a mutant beta toxin from Staphylococcus aureus reveals domain swapping and conformational flexibility.,Kruse AC, Huseby MJ, Shi K, Digre J, Ohlendorf DH, Earhart CA Acta Crystallogr Sect F Struct Biol Cryst Commun. 2011 Apr 1;67(Pt, 4):438-41. Epub 2011 Mar 24. PMID:21505235^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.