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
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