Integrative multiomic characterization of the methylome and restriction-modification repertoire of Mycoplasma hyorhinis SK76
Year: 2026
Type: article
Abstract: Restriction-modification (R-M) systems are widespread in Mycoplasma species, contributing to defense against foreign DNA and epigenetic regulation. However, the limited genetic tractability of Mollicutes hinders the functional characterization of R-M systems. Here, we characterized the R-M repertoire of Mycoplasma hyorhinis SK76 by integrating comparative genomics, structural modeling, quantitative proteomics, and genome-wide methylome profiling. We found that SK76 encodes Type I, Type II and Type III R-M systems with some duplicated components. For Type I, HsdS2 was predicted to recognize a bipartite TA-N₆-ATC motif, which was detected as a secondary 6mA-associated methylation signature, whereas the remaining HsdS variants displayed features consistent with reduced functionality. Among the Type II R-M system, Mhy3 and its cognate endonuclease End3 were associated with the 5mC motif GATC, while the remaining predicted methyltransferases lacked both protein expression and corresponding methylation signatures. Regarding Type III, Mod1 was identified as the principal active adenine methyltransferase responsible for the asymmetric GGAT-centered methylation pattern, whereas additional Mod homologues likely represent phase-variable or conditionally regulated elements with limited activity. Overall, the functional methylome of M. hyorhinis represents only a subset of its genomic R-M repertoire, underscoring the value of integrating genomic, proteomic and methylome data to define active epigenetic systems.
Source: Frontiers in Microbiology
Language: English
Subfield: Microbiology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7223183807