citation_publication_date: 2018-03-29T10:15:07Z msapplication-square70x70logo: //web-static.figshare.com/assets/ef6e8637cc252600e22cd4c1d755b4b771120789/public/global/favicon/mstile-70x70.png citation_title: Supplementary material from "Excision of the doubly methylated base N4,5-dimethylcytosine from DNA by Escherichia coli Nei and Fpg proteins" twitter:card: summary og:site_name: figshare twitter:url: https://figshare.com/collections/Supplementary_material_from_Excision_of_the_doubly_methylated_base_i_N_i_4_5-dimethylcytosine_from_DNA_by_i_Escherichia_coli_i_Nei_and_Fpg_proteins_/4024486 csrf_token: 315abb22-b4d5-4470-b84d-958faa413d29 msapplication-wide310x150logo: //web-static.figshare.com/assets/ef6e8637cc252600e22cd4c1d755b4b771120789/public/global/favicon/mstile-310x150.png description: Supplementary material from "Excision of the doubly methylated base N4,5-dimethylcytosine from DNA by Escherichia coli Nei and Fpg proteins" title: Supplementary material from "Excision of the doubly methylated base N4,5-dimethylcytosine from DNA by Escherichia coli Nei and Fpg proteins" og:description: Cytosine (C) in DNA is often modified to 5-methylcytosine (m⁵C) to execute important cellular functions. Despite the significance of m⁵C for epigenetic regulation in mammals, damage to m⁵C has received little attention. For instance, almost no studies exist on erroneous methylation of m⁵C by alkylating agents to doubly or triply methylated bases. Owing to chemical evidence, and because many prokaryotes express methyltransferases able to convert m⁵C into N⁴,5-dimethylcytosine (m^N^4,5C) in DNA, m^N^4,5C is probably present in vivo. We screened a series of glycosylases from prokaryotic to human and found significant DNA incision activity of the Escherichia coli Nei and Fpg proteins at m^N^4,5C residues in vitro. The activity of Nei was highest opposite cognate guanine followed by adenine, thymine (T) and C. Fpg-complemented Nei by exhibiting the highest activity opposite C followed by lower activity opposite T. To our knowledge, this is the first description of a repair enzyme activity at a further methylated m⁵C in DNA, as well as the first alkylated base allocated as a Nei or Fpg substrate. Based on our observed high sensitivity to nuclease S1 digestion, we suggest that m^N^4,5C occurs as a disturbing lesion in DNA and that Nei may serve as a major DNA glycosylase in E. coli to initiate its repair.This article is part of a discussion meeting issue ?Frontiers in epigenetic chemical biology?. twitter:site: @figshare DC.identifier: doi:10.6084/m9.figshare.c.4024486.v2 msapplication-square310x310logo: //web-static.figshare.com/assets/ef6e8637cc252600e22cd4c1d755b4b771120789/public/global/favicon/mstile-310x310.png dc:title: Supplementary material from "Excision of the doubly methylated base N4,5-dimethylcytosine from DNA by Escherichia coli Nei and Fpg proteins" Content-Encoding: UTF-8 Content-Type-Hint: text/html; charset=utf-8 Content-Type: text/html; charset=UTF-8 application-name: X-Parsed-By: org.apache.tika.parser.DefaultParser twitter:title: Supplementary material from "Excision of the doubly methylated base N4,5-dimethylcytosine from DNA by Escherichia coli Nei and Fpg proteins" og:type: article og:title: Supplementary material from "Excision of the doubly methylated base N4,5-dimethylcytosine from DNA by Escherichia coli Nei and Fpg proteins" citation_author: Alexeeva, Marina google: notranslate abstract: Cytosine (C) in DNA is often modified to 5-methylcytosine (m⁵C) to execute important cellular functions. Despite the significance of m⁵C for epigenetic regulation in mammals, damage to m⁵C has received little attention. For instance, almost no studies exist on erroneous methylation of m⁵C by alkylating agents to doubly or triply methylated bases. Owing to chemical evidence, and because many prokaryotes express methyltransferases able to convert m⁵C into N⁴,5-dimethylcytosine (m^N^4,5C) in DNA, m^N^4,5C is probably present in vivo. We screened a series of glycosylases from prokaryotic to human and found significant DNA incision activity of the Escherichia coli Nei and Fpg proteins at m^N^4,5C residues in vitro. The activity of Nei was highest opposite cognate guanine followed by adenine, thymine (T) and C. Fpg-complemented Nei by exhibiting the highest activity opposite C followed by lower activity opposite T. To our knowledge, this is the first description of a repair enzyme activity at a further methylated m⁵C in DNA, as well as the first alkylated base allocated as a Nei or Fpg substrate. Based on our observed high sensitivity to nuclease S1 digestion, we suggest that m^N^4,5C occurs as a disturbing lesion in DNA and that Nei may serve as a major DNA glycosylase in E. coli to initiate its repair.This article is part of a discussion meeting issue ?Frontiers in epigenetic chemical biology?. msapplication-square150x150logo: //web-static.figshare.com/assets/ef6e8637cc252600e22cd4c1d755b4b771120789/public/global/favicon/mstile-150x150.png msapplication-TileColor: #FFFFFF referrer: origin viewport: width=device-width, initial-scale=1 twitter:description: Cytosine (C) in DNA is often modified to 5-methylcytosine (m⁵C) to execute important cellular functions. Despite the significance of m⁵C for epigenetic regulation in mammals, damage to m⁵C has received little attention. For instance, almost no studies exist on erroneous methylation of m⁵C by alkylating agents to doubly or triply methylated bases. Owing to chemical evidence, and because many prokaryotes express methyltransferases able to convert m⁵C into N⁴,5-dimethylcytosine (m^N^4,5C) in DNA, m^N^4,5C is probably present in vivo. We screened a series of glycosylases from prokaryotic to human and found significant DNA incision activity of the Escherichia coli Nei and Fpg proteins at m^N^4,5C residues in vitro. The activity of Nei was highest opposite cognate guanine followed by adenine, thymine (T) and C. Fpg-complemented Nei by exhibiting the highest activity opposite C followed by lower activity opposite T. To our knowledge, this is the first description of a repair enzyme activity at a further methylated m⁵C in DNA, as well as the first alkylated base allocated as a Nei or Fpg substrate. Based on our observed high sensitivity to nuclease S1 digestion, we suggest that m^N^4,5C occurs as a disturbing lesion in DNA and that Nei may serve as a major DNA glycosylase in E. coli to initiate its repair.This article is part of a discussion meeting issue ?Frontiers in epigenetic chemical biology?. og:locale: en_US og:url: https://figshare.com/collections/Supplementary_material_from_Excision_of_the_doubly_methylated_base_i_N_i_4_5-dimethylcytosine_from_DNA_by_i_Escherichia_coli_i_Nei_and_Fpg_proteins_/4024486 Content-Language: en msapplication-TileImage: //web-static.figshare.com/assets/ef6e8637cc252600e22cd4c1d755b4b771120789/public/global/favicon/mstile-144x144.png