Structure of a mutant [beta] toxin from Staphylococcus aureus reveals domain swapping and conformational flexibility

Journal Article · Fri Sep 16 04:00:00 EDT 2011 · Acta Crystallogr. F

DOI:https://doi.org/10.1107/S1744309111005239· OSTI ID:1021791

Kruse, Andrew C; Huseby, Medora J; Shi, Ke; Digre, Jeff; Ohlendorf, Douglas H; Earhart, Cathleen A ^[1]

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1. UMM

The 3.35 {angstrom} 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.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: UNIVERSITY
• OSTI ID: 1021791
• Journal Information: Acta Crystallogr. F, Journal Name: Acta Crystallogr. F Journal Issue: (4) ; 04, 2011 Vol. 67; ISSN 1744-3091
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIMERS
FLEXIBILITY
MONOMERS
MUTANTS
MUTATIONS
PROTEINS
RESOLUTION
STAPHYLOCOCCUS
TOXINS