{"id":16232,"date":"2022-07-07T19:12:51","date_gmt":"2022-07-07T12:12:51","guid":{"rendered":"https:\/\/bgrssb.icgbio.ru\/2022\/?p=16232"},"modified":"2022-09-20T10:31:54","modified_gmt":"2022-09-20T03:31:54","slug":"noncanonical-prokaryotic-x-family-dna-polymerases","status":"publish","type":"post","link":"https:\/\/bgrssb.icgbio.ru\/2022\/2022\/07\/07\/noncanonical-prokaryotic-x-family-dna-polymerases\/","title":{"rendered":"Noncanonical prokaryotic X family DNA polymerases"},"content":{"rendered":"<p><em>by Maria Prostova | Evgeniy Shilkin | Alexandra A. Kulikova | Alena Makarova | Sergei Ryazansky |<\/em><br \/>\n<em>Andrey Kulbachinskiy | Institute of Molecular Genetics, National Research Centre \u201cKurchatov Institute\u201d,<\/em><br \/>\n<em>Moscow 123182, Russia | Institute of Molecular Genetics, National Research Centre \u201cKurchatov<\/em><br \/>\n<em>Institute\u201d, Moscow 123182, Russia | Institute of Molecular Genetics, National Research Centre<\/em><br \/>\n<em>\u201cKurchatov Institute\u201d, Moscow 123182, Russia | Institute of Molecular Genetics, National Research<\/em><br \/>\n<em>Centre \u201cKurchatov Institute\u201d, Moscow 123182, Russia | Institute of Molecular Genetics, National<\/em><br \/>\n<em>Research Centre \u201cKurchatov Institute\u201d, Moscow 123182, Russia<\/em><\/p>\n<p>DNA polymerases of the X family (PolX) play essential functions in eukaryotic DNA repair.<br \/>\nPolX polymerases are also found in prokaryotes but their diversity and functions remain<br \/>\nlargely unstudied. We have performed a comprehensive bioinformatic analysis of<br \/>\nprokaryotic PolXs and found that they are widespread in bacteria and are also present in<br \/>\nseveral archaeal lineages. Most polymerases share a common architecture, with the central<br \/>\npolymerase part consisting of the thumb, palm and fingers domains, preceded by an Nterminal dRP-lyase domain and followed by a C-terminal exonuclease PHP domain.<br \/>\nUnexpectedly, we have revealed a previously unrecognized group of noncanonical PolXs<br \/>\nthat seem to be lacking DNA polymerase activity. They contain substitutions of key catalytic<br \/>\nresidues and deletions in their polymerase and dNTP binding sites in the palm and fingers<br \/>\ndomains, but contain a functional exonuclease domain. Biochemical experiments with<br \/>\nrepresentative noncanonical PolXs from the Deinococcus genus confirmed that they are<br \/>\nindeed inactive as DNA polymerases but are highly efficient 3\u2019-5\u2019 exonucleases. The<br \/>\nbiological function of altered polymerases is possibly connected with double-strand break<br \/>\nDNA repair, since both canonical and altered PolXs are often encoded together with the<br \/>\ncomponents of the non-homologous end joining pathway, suggesting an evolutionary<br \/>\nconservation of this PolX function. This is a remarkable example of polymerases that have<br \/>\nlost their main polymerase activity, but may be involved in the nuclease processing of DNA<br \/>\nrepair intermediates.<\/p>\n<a href=\"https:\/\/bgrssb.icgbio.ru\/2022\/wp-content\/uploads\/sites\/3\/2022\/07\/novosib_poster.pdf\" class=\"pdfemb-viewer\" style=\"\" data-width=\"max\" data-height=\"max\"  data-toolbar=\"bottom\" data-toolbar-fixed=\"off\">novosib_poster<br\/><\/a>\n","protected":false},"excerpt":{"rendered":"<p>by Maria Prostova | Evgeniy Shilkin | Alexandra A. Kulikova | Alena Makarova | Sergei Ryazansky | Andrey Kulbachinskiy | Institute of Molecular Genetics, National Research Centre \u201cKurchatov Institute\u201d, Moscow 123182, Russia | Institute of Molecular Genetics, National Research Centre \u201cKurchatov Institute\u201d, Moscow 123182, Russia | Institute of Molecular Genetics, National Research Centre \u201cKurchatov Institute\u201d, [&hellip;]<\/p>\n","protected":false},"author":3967,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[5],"tags":[418,419,417,420,421],"_links":{"self":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts\/16232"}],"collection":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/users\/3967"}],"replies":[{"embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/comments?post=16232"}],"version-history":[{"count":2,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts\/16232\/revisions"}],"predecessor-version":[{"id":18079,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/posts\/16232\/revisions\/18079"}],"wp:attachment":[{"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/media?parent=16232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/categories?post=16232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bgrssb.icgbio.ru\/2022\/wp-json\/wp\/v2\/tags?post=16232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}