Fig. 1

Generalized principles of metabolite-responsible transcriptional factors (MRTFs) in biological systems. a Repressor binds with TFBS (typically, an operator) to block RNA polymerase for transcribing the target gene. Metabolite abolishes repression by removing the roadblock. b Repressor binds with metabolite (co-repressor) to form an active transcriptional roadblock and prevents transcription. c Activator binds with TFBS (typically, an enhancer element) to recruit RNA polymerase for transcribing the target gene. Metabolites abolishes activation by removing the activator. d Activator binds with metabolite (co-activator) to form an active transcriptional recruiter and accelerates transcription. TFBS: transcriptional factor binding sites