Phosphorylation of the mycobacterial transcriptional activator, EmbR, is essential for transcriptional regulation of theembCABoperon encoding cell wall arabinosyltransferases. This signaling pathway eventually affects the resistance to ethambutol (a frontline antimycobacterial drug) and the cell wall Lipoarabinomannan⁄Lipomannan ratio (an important determinant for averting the host immune response).