Abstract
Helicobacter pylori (hereafter H. pylori) is a gram-negative bacterium, which colonizes the gastric mucosa of humans, causing gastritis and peptic ulcer disease, and is associated with certain types of gastric cancers. In 1994, the International Agency for Cancer Research announced that H. pylori is a carcinogen of humans. Two complete genome sequences of the gastric pathogen H. pylori, 26695 and J99, have been determined in 1997. We chose H. pylori strain 26695 as the target genome of the structural genomics study by X-ray crystallography method. The major goal is to provide the significant and detailed structural information of the low homologous proteins in H. pylori. Another goal is to discovery the new structural folds. Three low homologous proteins were selected based on the criteria: acid induced or flagella associated. A structure-based homology analysis with the DALI algorithm was applied to the structure analysis. One of the solved structures is a new fold with four helices folded into a triangle. The other two proteins reported in flagella assembly or regulatory in which one structure demonstrates the characteristics in flagella assembly feature and the other structure matches most of the RNA/DNA binding protein. Our results may shed a light on further functional studies based on their unique protein folding.