Evolution of functional polymorphism in the gene coding for the Helicobacter pylori cytotoxin.
نویسندگان
چکیده
There are two functionally different alleles of the Helicobacter pylori vacA gene, which code for proteins with different in target cell specificity. The alleles (m1 and m2) differ by approximately 50% in amino acid sequence in a 300 amino acid region, the m-region, which determines specificity. An analysis of partial likelihood anomalies in a set of eight Chinese and six Western vacA genes revealed highly significant phylogenetic deviation of a region of the gene including the m-region. Phylogenetic analysis of the conserved regions of these genes failed to reveal any distinction between m1 alleles and m2 alleles, however clear cut geographic variation was observed. In the m-region, the m1 alleles also show separate clustering of Chinese and Western isolates, however the m-region of the m2 alleles has a phylogenetic structure markedly different from the rest of the gene. The data indicate that the m2 m-region was acquired and spread through the population by horizontal transfer of DNA.
منابع مشابه
Seroprevalence of anti-Helicobacter pylori and anti-cytotoxin-associated gene A antibodies among healthy individuals in center of Iran
Objective(s):Helicobacter pylori infection occurs worldwide, but the prevalence of this infection varies greatly among different countries and population groups. The aim of this study was to determine the seroprevalence of anti-Helicobacter pylori and anti-cytotoxin-associated gene A (CagA) antibodies in asymptomatic healthy population in the center of Iran and to investigate the relation with ...
متن کاملVacuolating Cytotoxin of Helicobacter pylori
Vacuolating cytotoxin (VacA) is one of the most important virulence factors of H. pylori (Hp), which isthe only toxic protein that is secreted from Hp cell into the culture supernatant. The effects of VacA oneukaryotic systems is the subject of many previous and on going research studies. Intracellular targetsfor this toxin include: late endosomal and lysosomal compartments, m...
متن کاملVacA and cagA genotypes status and antimicrobial resistance properties of Helicobacter pylori strains isolated from meat products in Isfahan province, Iran
Although Helicobacter pylori has a significant impact on the occurrence of severe clinical syndromes, its exact ways of transmission and origin have not been identified. According to the results of some previously published articles, foods with animal origins play a substantial role in the transmission of H. pylori to humans. The present investigation was carried out to study the vacuolating cy...
متن کاملExpression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori
Objective(s): Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity. Materials and Methods: The antigenic region of V...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- FEMS microbiology letters
دوره 206 2 شماره
صفحات -
تاریخ انتشار 2002