Purification, crystallization and preliminary crystallographic analysis of Chlamydophila pneumoniae AP endonuclease IV

Protein Expr Purif. 2024 Jul:219:106476. doi: 10.1016/j.pep.2024.106476. Epub 2024 Mar 22.

Abstract

Base excision is a crucial DNA repair process mediated by endonuclease IV in nucleotide excision. In Chlamydia pneumoniae, CpendoIV is the exclusive AP endonuclease IV, exhibiting DNA replication error-proofreading capabilities, making it a promising target for anti-chlamydial drug development. Predicting the structure of CpendoIV, molecular docking with DNA was performed, analyzing complex binding sites and protein surface electrostatic potential. Comparative structural studies were conducted with E. coli EndoIV and DNA complex containing AP sites.CpendoIV was cloned, expressed in E. coli, and purified via Ni-NTA chelation and size-exclusion chromatography. Low NaCl concentrations induced aggregation during purification, while high concentrations enhanced purity.CpendoIV recognizes and cleaving AP sites on dsDNA, and Zn2+ influences the activity. Crystallization was achieved under 8% (v/v) Tacsimate pH 5.2, 25% (w/v) polyethylene glycol 3350, and 1.91 Å resolution X-ray diffraction data was obtained at 100 K. This research is significant for provides a deeper understanding of CpendoIV involvement in the base excision repair process, offering insights into Chlamydia pneumoniae.

Keywords: Chlamydia pneumoniae; Crystallization; DNA repair; Endonuclease IV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins* / chemistry
  • Bacterial Proteins* / genetics
  • Bacterial Proteins* / isolation & purification
  • Chlamydophila pneumoniae* / chemistry
  • Chlamydophila pneumoniae* / enzymology
  • Chlamydophila pneumoniae* / genetics
  • Cloning, Molecular
  • Crystallization*
  • Crystallography, X-Ray
  • Deoxyribonuclease IV (Phage T4-Induced) / chemistry
  • Deoxyribonuclease IV (Phage T4-Induced) / genetics
  • Deoxyribonuclease IV (Phage T4-Induced) / isolation & purification
  • Deoxyribonuclease IV (Phage T4-Induced) / metabolism
  • Escherichia coli / genetics
  • Molecular Docking Simulation
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism

Substances

  • Bacterial Proteins
  • Recombinant Proteins
  • Deoxyribonuclease IV (Phage T4-Induced)