Analysis of Variations in Conserved Motifs of Cag A protein in Different Helicobacter Pylori Strains

Author Name(s): Bharathi
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Infection with strains of Helicobacter pylori that carry the cytotoxin-associated antigen a (cagA) gene is associated with gastric carcinoma. Recent studies have shed light on the mechanism through which the cagA gene product, CagA, elicits pathophysiological actions. Helicobacter pylori infection has an association with histological gastritis, gastric atrophy, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma in the stomach. There are some strains of H. pylori that are capable of triggering a greater inflammatory response in the stomach of its host. This strain carries the cag pathogenicity island (cag PAI).The research work deals with analysis and prediction of structural motif of cagA protein present in different strains of helicobacter pylori. The variations among the motifs in different strains are analyzed. The significant motif showing highest variability is traced. Through this changes in the conserved region of the motif the variability among different strains were studied.


Gastric carcinoma, Gastric atrophy, MALT, pathophysiological


Gastric cancer is commonly referred to as stomach cancer which can develop in any part of the stomach and may spread throughout the stomach and to other organs; particularly the esophagus, lungs, lymph nodes, and the liver. Most stomach cancers start in the mucosa. Stomach cancer causes about 800,000 deaths worldwide per year. There are three main types of stomach cancers: lymphomas, gastric stomal tumors, and carcinoid tumors. Stomach cancer can cause the, Indigestion or burning sensation (heartburn), Loss of appetite, especially for meat, Abdominal discomfort or irritation, Weakness and fatigue. The three main treatments for stomach cancer are surgery, chemotherapy, and radiation therapy.
Helicobacter pylorus (also known as H.pylori) is a spiral-shaped bacterium that lives in the lining of the stomach. Helicobacter pylori CagA protein is associated with severe gastritis and gastric carcinoma.


There are different strains in Helicobacter pylori which are responsible for gastric cancer. Motifs of biological significance like the regions which contribute for the protein function and structure has been studied. Through the analysis of motifs we have analyzed the variations among different strains which might be the possible reason for the evolution of different strains. Future studies may be undertaken on next probable variation and new upcoming strains of H Pylori may be predicted. It may help and fetch interest of pharma community to undertake Research on designing and developing drugs against gastric cancer which may be caused by a new strain in future.

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