Binding site of restriction-modification system controller protein in Mollicutes

Gleb Y Fisunov,Vadim M Govorun,Daria V Evsyutina,Valentin A Manuvera

doi:10.1186/s12866-017-0935-4

Gleb Y Fisunov, Vadim M Govorun + Show 2 more

Open Access

https://doi.org/10.1186/s12866-017-0935-4

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Abstract

BackgroundBacteria of the class Mollicutes underwent extreme reduction of genomes and gene expression control systems. Only a few regulators are known to date. In this work, we describe a novel group of transcriptional regulators that are distributed within different Mollicutes and control the expression of restriction-modification systems (RM-systems).ResultsWe performed cross-species search of putative regulators of RM-systems (C-proteins) and respective binding sites in Mollicutes. We identified a set of novel putative C-protein binding motifs distributed within Mollicutes. We studied the most frequent motif and respective C-protein on the model of Mycoplasma gallisepticum S6. We confirmed our prediction and identified key nucleotides important for C-protein binding. Further we identified novel target promoters of C-protein in M. gallisepticum.ConclusionsWe found that C-protein of M. gallisepticum binds predicted conserved direct repeats of the (GTGTTAN5)2 motif. Apart from its own operon promoter, HsdC can bind to the promoters of the clpB chaperone gene and a tRNA cluster.

Highlights

Bacteria of the class Mollicutes underwent extreme reduction of genomes and gene expression control systems
The study of transcriptional regulation in mycoplasmas contributes to two topics: the adaptation of an efficient parasite using a minimal amount of regulators and the organization of gene expression regulation in the core cellular machinery
Homologs of Cproteins were distributed within different groups of Mollicutes, including Acholeplasmatales and Mycoplasmatales (Fig. 1, Table 2, Additional file 1: Table S1), but their similarity was not very high (60–40% on average)

Summary

Introduction

Bacteria of the class Mollicutes underwent extreme reduction of genomes and gene expression control systems. We describe a novel group of transcriptional regulators that are distributed within different Mollicutes and control the expression of restriction-modification systems (RM-systems). Mollicutes are wall-less bacteria with a significantly reduced genome. The repertoire of gene expression regulators in Mollicutes is reduced as well. The ability of mycoplasmas to adapt to different conditions contrasts with the small amount of regulators. Mycoplasmas are used as model objects for systems biology to study the core organization of living cells. The study of transcriptional regulation in mycoplasmas contributes to two topics: the adaptation of an efficient parasite using a minimal amount of regulators and the organization of gene expression regulation in the core cellular machinery

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