GlnR Regulates the Glyoxylate Cycle and the Methylcitrate Cycle on Fatty Acid Metabolism by Repressing Transcription.

(), along with its pathogenic counterpart (), utilizes fatty acids and cholesterol as important carbon and energy sources during the persistence within host cells. As a dual-functional enzyme in the glyoxylate cycle and the methylcitrate cycle, isocitrate lyase (ICL, encoded by or ) is indispensable for the growth of and on short-chain fatty acids. However, regulation of in mycobacteria in response to nutrient availability remains largely unknown.

The Nitrogen Regulator GlnR Directly Controls Transcription of the Operon Involved in Methylcitrate Cycle in Mycobacterium smegmatis.

utilizes fatty acids of the host as the carbon source. Metabolism of odd-chain fatty acids by produces propionyl coenzyme A (propionyl-CoA). The methylcitrate cycle is essential for mycobacteria to utilize the propionyl-CoA to persist and grow on these fatty acids.