Analyzing of expression of novel polypeptide complexes consisting of Shiga toxin B subunit and Adherence Fimbriae of Escherichia coli based on in silico modeling
Autor: | Mana Oloomi, Saeid Bouzari, Zeinab Noroozian |
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Přispěvatelé: | Institut Pasteur d'Iran, Réseau International des Instituts Pasteur (RIIP), Molecular Biology Department, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP) |
Jazyk: | angličtina |
Rok vydání: | 2012 |
Předmět: |
Models
Molecular Pentamer Fimbria Blotting Western medicine.disease_cause Shiga Toxins Catalysis Bacterial Adhesion Protein Structure Secondary Inorganic Chemistry 03 medical and health sciences Intestinal mucosa medicine polycyclic compounds Escherichia coli Shiga toxin B subunit Disulfides Physical and Theoretical Chemistry 030304 developmental biology 0303 health sciences Adhesins Escherichia coli biology 030306 microbiology Escherichia coli Proteins Aggregative adherence fimbriae Organic Chemistry Computational Biology Protein complex Shiga toxin AB5 toxin Molecular biology [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM] Protein tertiary structure Computer Science Applications Protein Structure Tertiary Bacterial adhesin Protein Subunits Computational Theory and Mathematics biology.protein Electrophoresis Polyacrylamide Gel Fimbriae Proteins [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM] Peptides Protein Binding |
Zdroj: | J Mol Model J Mol Model, 2012, 18 (9), pp.4131-9. ⟨10.1007/s00894-012-1414-3⟩ |
Popis: | International audience; Enterohemorrhagic (EHEC) and enteroaggregative (EAEC) are two pathotypes of diarrheagenic Escherichia coli. EAEC strains express adhesins called aggregate adherence fimbriae (AAFs) which the bacteria use to adhere to intestinal mucosa. EHEC virulence factor is Shiga toxin which belongs to the AB5 toxin family. B subunit, the nontoxic part of Shiga toxin (StxB), forms a homo pentamer and is responsible for binding to target cells. StxB has recently been proven to have adjuvant activity. In the current study we fused StxB encoding gene to 3' end of genes encoding two variants of AAFs, i.e., AAF/I and AAF/II. The in silico studies on tertiary structure and biochemical characteristics of Shiga toxin A subunit (StxA) revealed more resemblance to AAF/II than AAF/I. The constructs were prepared in a way that StxB could imitate its natural structure (pentamer formation) and its position (C-terminus) in the native toxin complex. The expression of these constructs showed the formation of AAF/II-B as a protein complex but with lower molecular mass than its expected size. In contrast, the AAF/I-B complex was not formed. Overall, the results of in silico studies and expression experiments together revealed that despite AAF/II-B expression, StxB failed to form pentamer. Therefore the observed protein complex has lower molecular mass. Since StxB is bound to AAF/II through disulfide bond, this bond prevents pentamer formation of StxB. However, due to the lack of disulfide bond between AAF/I and StxB, no protein complex is formed, thus StxB maintains its pentamer structure. |
Databáze: | OpenAIRE |
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