20 years of DNA Polymerase μ, the polymerase that still surprises

Abstract

DNA polymerases are important enzymes involved in DNA replication and repair. Based on sequence homology, DNA polymerases have been grouped into distinct families, which are A, B, X, and Y. The Pol X family consists of four members: Pol k, l, and b and terminal transferase or TdT. Members of the family X are involved in base excision repair, nonhomologous end joining (NHEJ), and V(D)J recombination. One of the most interesting pol X family members is DNA polymerase l, discovered back in 2000. Subsequent studies established the importance of Pol l as a repair polymerase in NHEJ and its interactions with the other proteins of the NHEJ machinery. Pol l has a number of interesting properties, which sets it apart from the other known DNA polymerases, including its ability to synthesize DNA from an unpaired primer terminus as well in the complete absence of a template strand (terminal transferase activity). Another standout property of Pol l is its reduced ability to discriminate between ribonucleotides and deoxyribonucleotides and its ability to utilize both ribonucleotides and deoxyribonucleotides as substrates during the gap-filling stage of NHEJ. In this review, we provide a brief overview of Pol l in double-strand break repair and the current knowledge on its various functional aspects.

Isolation, characterization and therapeutic evaluation of a new Acinetobacter virus Abgy202141 lysing Acinetobacter baumannii

“…ORF12 is predicted to be the DNA polymerase. It plays an important role in DNA replication and repair (Ghosh and Raghavan, 2021 ). ORF13 is predicted to be the DNA ligase.…”

Transcriptional immune suppression and upregulation of double stranded DNA damage and repair repertoires in ecDNA-containing tumors

“…A number of genes involved in c-NHEJ were downregulated in ecDNA-containing tumors relative to non-ecDNA tumors. These included XLF / NHEJ1 (MWU p -value 2.05e-03), which is a key member of the ligase complex required for c-NHEJ; LIG4 , another member of the ligase complex (MWU p -value 0.03), PNKP , which generates 5΄-phosphate/3΄-hydroxyl DNA termini required for ligation (MWU p- value 3.90e-06); and also, DNA polymerases λ ( POLL ; MWU p -value 1.09e-21) and μ ( POLM ; MWU p -value 0.01), which promotes the ligation of terminally compatible overhangs requiring fill-in synthesis and promotes the ligation of incompatible 3ʹ overhangs 31 in a template independent manner, respectively. This does not imply a defect in these repair processes, but rather, potentially additional or preferential utilization of alternative DSB repair pathways in ecDNA-containing tumors.…”

Revisión bibliográfica: Función e importancia de las ADN polimerasas

“…La Pol II de Escherichia coli, de igual manera es considerada un miembro de la familia B de polimerasas. Albergando la actividad de corrección exonucleasa 3'-5', asociada al reinicio de la replicación y a la síntesis de translesión de ADN (13).…”