title: Type IV secretion system in Helicobacter pylori: a new insight into pathogenicity.
abstract: OBJECTIVE
  To review the research progress on Type IV secretion system (T4SS) in Helicobacter pylori.
  
  
  METHODS
  The data used in this review were identified by searching of PUBMED (1995 - 2007) online resources using the key terms 'Type IV secretion system' and 'Helicobacter pylori'.
  
  
  METHODS
  Mainly original articles and critical reviews written by major pioneer investigators of this field were selected.
  
  
  RESULTS
  The research progress on T4SS in Helicobacter pylori was summarized. The structure and function was discussed.
  
  
  CONCLUSIONS
  T4SS is not only involved in toxin secretion and injection of virulence factors into eukaryotic host target cells, but also involved in horizontal DNA transfer to other bacteria and eukaryotic cells, through DNA uptake from or release into the extracellular milieu. It provides a new insight into the pathogenicity of Helicobacter pylori and a novel target for antimicrobials development. However, many challenges remain for us in understanding the biological role of T4SS in Helicobacter pylori.
authors.affiliation: Department of Medical Microbiology and Parasitology, School of Medical Technology, Jiangsu University, Zhenjiang, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Zhong
authors.forename: Shi-he
authors.initials: SH
authors.lastname: Shao
authors.forename: Lei-lei
authors.initials: LL
authors.lastname: Cui
authors.forename: Run-hong
authors.initials: RH
authors.lastname: Mu
authors.forename: Xiao-li
authors.initials: XL
authors.lastname: Ju
authors.forename: Su-rong
authors.initials: SR
authors.lastname: Dong
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins; D022761:Gene Transfer, Horizontal; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D005810:Multigene Family
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C061261:comB protein, Haemophilus influenzae