NMR structure of the Bacillus cereus hemolysin II C-terminal domain reveals a novel fold

Autor: Anne R. Kaplan, Katherine Kaus, Swastik De, Rich Olson, Andrei T. Alexandrescu
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Scientific Reports, Vol 7, Iss 1, Pp 1-13 (2017)
Druh dokumentu: article
ISSN: 2045-2322
DOI: 10.1038/s41598-017-02917-4
Popis: Abstract In addition to multiple virulence factors, Bacillus cereus a pathogen that causes food poisoning and life-threatening wound infections, secretes the pore-forming toxin hemolysin II (HlyII). The HlyII toxin has a unique 94 amino acid C-terminal domain (HlyIIC). HlyIIC exhibits splitting of NMR resonances due to cis/trans isomerization of a single proline near the C-terminus. To overcome heterogeneity, we solved the structure of P405M-HlyIIC, a mutant that exclusively stabilizes the trans state. The NMR structure of HlyIIC reveals a novel fold, consisting of two subdomains αA-β1-β2 and β3-β4-αB-β5, that come together in a barrel-like structure. The barrel core is fastened by three layers of hydrophobic residues. The barrel end opposite the HlyIIC-core has a positively charged surface, that by binding negatively charged moieties on cellular membranes, may play a role in target-cell surface recognition or stabilization of the heptameric pore complex. In the WT domain, dynamic flexibility occurs at the N-terminus and the first α-helix that connects the HlyIIC domain to the HlyII-core structure. In the destabilizing P405M mutant, increased flexibility is evident throughout the first subdomain, suggesting that the HlyIIC structure may have arisen through gene fusion.
Databáze: Directory of Open Access Journals
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