Tipalpha is secreted from H. pylori as dimers and enters the gastric cells. It binds to DNA via the positively charged surface-patch formed between the two monomers of the crystal structure by the loop between helices alpha1 and alpha2. Each monomer consists of a helical domain and a mixed domain [1].

1: Structural and mechanistic studies of pesticin, a bacterial homolog of phage lysozymes. Patzer SI, Albrecht R, Braun V, Zeth K; J Biol Chem. 2012;287:23381-23396. PMID:22593569

2: Crystal structure of the TNF-alpha-Inducing protein (Tipalpha) from Helicobacter pylori: Insights into Its DNA-binding activity. Jang JY, Yoon HJ, Yoon JY, Kim HS, Lee SJ, Kim KH, Kim do J, Jang S, Han BG, Lee BI, Suh SW; J Mol Biol. 2009;392:191-197. PMID:19596016