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A thermostable DNA primase‐polymerase from a mobile genetic element involved in defence against environmental DNA
Author(s) -
GarcíaQuintans Nieves,
Baquedano Ignacio,
Blesa Alba,
Verdú Carlos,
Berenguer José,
Mencía Mario
Publication year - 2020
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.15207
Subject(s) - biology , primase , dna polymerase , mutant , genetics , dna , dna replication , primer (cosmetics) , polymerase , mutagenesis , plasmid , dna polymerase ii , thermus thermophilus , gene , polymerase chain reaction , reverse transcriptase , chemistry , organic chemistry , escherichia coli
Summary Primase‐polymerases (Ppol) are one of the few enzymes able to start DNA synthesis on ssDNA templates. The role of Thermus thermophilus HB27 Ppol, encoded along a putative helicase (Hel) within a mobile genetic element (ICETh2), has been studied. A mutant lacking Ppol showed no effects on the replication of the element. Also, no apparent differences in the sensitivity to DNA damaging agents and other stressors or morphological changes in the mutant cells were detected. However, the mutants lacking Ppol showed an increase in two to three orders of magnitude in their transformation efficiency with plasmids and genomic DNA acquired from the environment (eDNA), independently of its origin and G + C content. In contrast, no significant differences with the wild type were detected when the cells received the DNA from other T. thermophilus partners in conjugation‐like mating experiments. The similarities of this behaviour with that shown by mutants lacking the Argonaute (ThAgo) protein suggests a putative partnership Ppol‐ThAgo in the DNA–DNA interference mechanism of defence, although other eDNA defence mechanisms independent of ThAgo cannot be discarded.