2n67

Publication Abstract from PubMed

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 alphaA-beta1-beta2 and beta3-beta4-alphaB-beta5, 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 alpha-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.

NMR structure of the Bacillus cereus hemolysin II C-terminal domain reveals a novel fold.,Kaplan AR, Kaus K, De S, Olson R, Alexandrescu AT Sci Rep. 2017 Jun 12;7(1):3277. doi: 10.1038/s41598-017-02917-4. PMID:28607368^[1]

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