Mimivirus encodes a multifunctional primase with DNA/RNA polymerase, terminal transferase and translesion synthesis activities.

Authors:
Ankita Gupta
Ankita Gupta
North-Eastern Hill University
India
Pratibha P Ghodke
Pratibha P Ghodke
Indian Institute of Technology Bombay
Dr. Kiran Kondabagil, PhD
Dr. Kiran Kondabagil, PhD
Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay
Assistant Professor
Molecular Virology, Molecular motors
Mumbai, Maharshtra | INDIA

Nucleic Acids Res 2019 Apr 19. Epub 2019 Apr 19.

Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra 400076, India.

Acanthamoeba polyphaga mimivirus is an amoeba-infecting giant virus with over 1000 genes including several involved in DNA replication and repair. Here, we report the biochemical characterization of gene product 577 (gp577), a hypothetical protein (product of L537 gene) encoded by mimivirus. Sequence analysis and phylogeny suggested gp577 to be a primase-polymerase (PrimPol)-the first PrimPol to be identified in a nucleocytoplasmic large DNA virus (NCLDV). Recombinant gp577 protein purified as a homodimer and exhibited de novo RNA as well as DNA synthesis on circular and linear single-stranded DNA templates. Further, gp577 extends a DNA/RNA primer annealed to a DNA or RNA template using deoxyribonucleoties (dNTPs) or ribonucleotides (NTPs) demonstrating its DNA/RNA polymerase and reverse transcriptase activity. We also show that gp577 possesses terminal transferase activity and is capable of extending ssDNA and dsDNA with NTPs and dNTPs. Mutation of the conserved primase motif residues of gp577 resulted in the loss of primase, polymerase, reverse transcriptase and terminal transferase activities. Additionally, we show that gp577 possesses translesion synthesis (TLS) activity. Mimiviral gp577 represents the first protein from an NCLDV endowed with primase, polymerase, reverse transcriptase, terminal transferase and TLS activities.

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http://dx.doi.org/10.1093/nar/gkz236DOI Listing
April 2019
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References

(Supplied by CrossRef)
Primase, the dnaG protein of Escherichia coli
Enzyme et al.
J. Biol. Chem. 1978
Distinct domain functions regulating de Novo DNA synthesis of thermostable DNA primase from hyperthermophile pyrococcus horikoshii
Liu et al.
J. Biol. Chem. 2003

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