New England Biolabs and Pacific Biosciences researchers used the PacBio RS system to re-sequence the six bacterial genomes. Not only did they identify new cytosine and adenine methylation sites in the bacterial genome, they also identified mediating these appearances Genetic markers of methyltransferase. The research results were published in "Nucleic Acids Research" recently. In recent years, methylation research has continued to heat up. In mammals, the research focus continues from the fifth base 5-mC to 5-hmC, 5-fC and 5-caC. N6-methyladenine (m6A) and N4-methylcytosine (m4C) are also common in bacterial genomes, and they function as part of a restricted modification (RM) system. However, due to the lack of simple methods to locate these methylations, they are often overlooked. It was not until the advent of single-molecule real-time (SMRT) sequencing technology that the identification of these methylation modifications became simple. In this study, researchers from New England Biolabs (NEB) and PacBio re-sequenced six bacterial genomes. These six bacteria are: Geobacter metallireducens, Chromohalobacter salexigens, Vibrio breoganii, Bacillus cereus, and two subspecies of Campylobacter jejuni. These bacteria have also been sequenced on other platforms before, but this time the PacBio RS system was used to specifically analyze their methylomes. The methylated bases in the bacterial genome play an important role as part of the restriction modification system. They protect the host from the harmful effects of other restriction enzymes. However, in some cases, these methyltransferases (MTase) also play a regulatory role, introducing m6A residues and playing a role in DNA repair. The researchers previously cloned a single MTase gene onto a plasmid and propagated it in a methylation-deficient E. coli strain to analyze its recognition site. However, the results of the plasmid study are not very clear. Therefore, the researchers considered using the SMRT sequencing method to directly analyze the bacterial genome to obtain an accurate estimate of the degree of methylation. In this way, the researchers discovered multiple new N6-methyladenine (m6A) and N4-methylcytosine (m4C) methylation patterns in the bacterial genome, and designated those responsible for methylation patterns DNA methyltransferase. The author believes that SMRT sequencing can provide functional information for the active MTase present in the genome and decipher their recognition sequences. This method, as well as the long reads it brings, is a good aid to existing high-throughput sequencing platforms, which facilitates sequence assembly and reliably records gene functions. White Nightstand,Mirrored Nightstand,Floating Nightstand,Black Nightstand Bosa Furniture Co.,Ltd. , https://www.bosafurniture.com
Single molecule sequencing facilitates analysis of bacterial methylome