Plays an important role in bacterial chemotaxis signal transduction pathway by accelerating the dephosphorylation of phosphorylated CheY (CheY-P). Acts on free CheY-P. Homodimer. Interacts (via C-terminus) with phosphorylated CheY (CheY-P). Cells lacking this gene display a strong clockwise motor bias; in combination with a yhjH disruption and overexpression of ycgR, cells switch from clockwise to a counterclockwise bias. Belongs to the CheZ family.