title: Pseudomonas aeruginosa phage PaP1 DNA polymerase is an A-family DNA polymerase demonstrating ssDNA and dsDNA 3'-5' exonuclease activity.
abstract: Most phages contain DNA polymerases, which are essential for DNA replication and propagation in infected host bacteria. However, our knowledge on phage-encoded DNA polymerases remains limited. This study investigated the function of a novel DNA polymerase of PaP1, which is the lytic phage of Pseudomonas aeruginosa. PaP1 encodes its sole DNA polymerase called Gp90 that was predicted as an A-family DNA polymerase with polymerase and 3'-5' exonuclease activities. The sequence of Gp90 is homologous but not identical to that of other A-family DNA polymerases, such as T7 DNA polymerases (Pol) and DNA Pol I. The purified Gp90 demonstrated a polymerase activity. The processivity of Gp90 in DNA replication and its efficiency in single-dNTP incorporation are similar to those of T7 Pol with processive thioredoxin (T7 Pol/trx). Gp90 can degrade ssDNA and dsDNA in 3'-5' direction at a similar rate, which is considerably lower than that of T7 Pol/trx. The optimized conditions for polymerization were a temperature of 37 °C and a buffer consisting of 40 mM Tris-HCl (pH 8.0), 30 mM MgCl2, and 200 mM NaCl. These studies on DNA polymerase encoded by PaP1 help advance our knowledge on phage-encoded DNA polymerases and elucidate PaP1 propagation in infected P. aeruginosa.
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, People's Republic of China.
authors.forename: Binyan
authors.initials: B
authors.lastname: Liu
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, People's Republic of China.
authors.forename: Shiling
authors.initials: S
authors.lastname: Gu
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, People's Republic of China.
authors.forename: Nengsong
authors.initials: N
authors.lastname: Liang
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, People's Republic of China.
authors.forename: Mei
authors.initials: M
authors.lastname: Xiong
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, People's Republic of China.
authors.forename: Qizhen
authors.initials: Q
authors.lastname: Xue
authors.affiliation: Department of Microbiology, College of Basic Medical Science, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Lu
authors.affiliation: Department of Microbiology, College of Basic Medical Science, Third Military Medical University, Chongqing, People's Republic of China.
authors.forename: Fuquan
authors.initials: F
authors.lastname: Hu
authors.affiliation: Institute of Toxicology, College of Preventive Medicine, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing, 400038, People's Republic of China. huidongzhang@tmmu.edu.cn.
authors.forename: Huidong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics*; D004247:DNA / Q000235:genetics*; D004261:DNA Replication / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics*; D005092:Exonucleases / Q000235:genetics*; D000073718:Pancreatitis-Associated Proteins; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D016415:Sequence Alignment; D013879:Thioredoxins / Q000235:genetics
chemical_list: D004277:DNA, Single-Stranded; D000073718:Pancreatitis-Associated Proteins; C000612141:REG3A protein, human; D013879:Thioredoxins; D004247:DNA; D004259:DNA-Directed DNA Polymerase; D005092:Exonucleases
keywords: DNA polymerase; Exonuclease; Phage PaP1; Pseudomonas aeruginosa