Structural insight into β-Clamp and its interaction with DNA Ligase in Helicobacter pylori

Sci Rep. 2016 Aug 8:6:31181. doi: 10.1038/srep31181.

Abstract

Helicobacter pylori, a gram-negative and microaerophilic bacterium, is the major cause of chronic gastritis, gastric ulcers and gastric cancer. Owing to its central role, DNA replication machinery has emerged as a prime target for the development of antimicrobial drugs. Here, we report 2Å structure of β-clamp from H. pylori (Hpβ-clamp), which is one of the critical components of DNA polymerase III. Despite of similarity in the overall fold of eubacterial β-clamp structures, some distinct features in DNA interacting loops exists that have not been reported previously. The in silico prediction identified the potential binders of β-clamp such as alpha subunit of DNA pol III and DNA ligase with identification of β-clamp binding regions in them and validated by SPR studies. Hpβ-clamp interacts with DNA ligase in micromolar binding affinity. Moreover, we have successfully determined the co-crystal structure of β-clamp with peptide from DNA ligase (not reported earlier in prokaryotes) revealing the region from ligase that interacts with β-clamp.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • Crystallography, X-Ray
  • DNA Ligases / chemistry*
  • Helicobacter pylori / enzymology*
  • Protein Domains
  • Protein Structure, Secondary
  • Structure-Activity Relationship

Substances

  • Bacterial Proteins
  • DNA Ligases