Binding site of MraZ transcription factor in Mollicutes.Mollicutes (mycoplasmas) feature a significant loss of known regulators of gene expression.  Here, we identified the recognition site of the MraZ-family regulator of Mycoplasma gallisepticum, which is conserved in many species of different clades within class Mollicutes.  The MraZ binding site is AAAGTG[T/G], in the promoter of mraZ gene it forms a series of direct repeats with a structure (AAAGTG[T/G]N3)k, where k = 3 most frequently.  MraZ binds to a single repeat as an octamer complex.  MraZ can also bind a single binding site or a series of repeats with different spacer lengths (2-4 nt); thus, it may play a role in the regulation of multiple operons in Mollicutes.  In M. gallisepticum, MraZ acts as a transcriptional activator.  The overexpression of MraZ leads to moderate filamentation of cells and the formation of aggregates, likely as a result of incomplete cytokinesis.
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