Chlamydial DNA polymerase I can bypass lesions in vitro.
We found that DNA polymerase I from Chlamydiophila pneumoniae AR39 (CpDNApolI) presents DNA-dependent DNA polymerase activity, but has no detectable 3' exonuclease activity. CpDNApolI-dependent DNA synthesis was performed using DNA templates carrying different lesions. DNAs containing 2'-deoxyuridine (dU), 2'-deoxyinosine (dI) or 2'-deoxy-8-oxo-guanosine (8-oxo-dG) served as templates as effectively as unmodified DNAs for CpDNApolI. Furthermore, the CpDNApolI could bypass natural apurinic/apyrimidinic sites (AP sites), deoxyribose (dR), and synthetic AP site tetrahydrofuran (THF). CpDNApolI could incorporate any dNMPs opposite both of dR and THF with the preference to dAMP-residue. CpDNApolI preferentially extended primer with 3'-dAMP opposite dR during DNA synthesis, however all four primers with various 3'-end nucleosides (dA, dT, dC, and dG) opposite THF could be extended by CpDNApolI. Efficiently bypassing of AP sites by CpDNApolI was hypothetically attributed to lack of 3' exonuclease activity.
Liu
Xipeng
X
College of Life Sciences and Technology, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.
Hou
Jingli
J
Liu
Jianhua
J
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D016993:Chlamydophila pneumoniae / Q000201:enzymology* / Q000235:genetics; D004247:DNA / Q000737:chemistry; D004249:DNA Damage; D004256:DNA Polymerase I / Q000378:metabolism / Q000502:physiology*; D017931:DNA Primers / Q000737:chemistry; D005092:Exonucleases / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry; D012689:Sequence Homology, Nucleic Acid
D017931:DNA Primers; D011994:Recombinant Proteins; D004247:DNA; D004256:DNA Polymerase I; D005092:Exonucleases; C022650:spleen exonuclease