The pathway of trehalose utilization in Escherichia coli is different at low and high osmolarity. The low osmolarity system takes up trehalose as trehalose 6-phosphate which is hydrolyzed to glucose and glucose 6-phosphate. treB and treC, the genes for the enzymes involved, form an operon that is controlled by TreR (encoded by treR), the repressor of the system, for which trehalose 6-phosphate is the inducer. The trehalose effector pathway is a trehalose utilization process regulated by the transcriptional regulator TreR. TreR typically functions as a repressor and responds to the presence of trehalose, a disaccharide composed of two glucose molecules. Upon sensing trehalose, TreR undergoes a conformational change that reduces its DNA-binding affinity, thereby allowing transcription of downstream genes involved in trehalose metabolism. Key genes regulated by the TreR regulog include: amyE – Encodes α-amylase, which breaks down complex carbohydrates like starch into simpler sugars, potentially increasing trehalose availability or serving as an auxiliary component in broader carbohydrate metabolism. treE – Encodes trehalase, an enzyme that hydrolyzes trehalose into two glucose molecules, enabling their entry into glycolytic pathways for energy production. treF – Typically encodes a cytoplasmic trehalase, also responsible for degrading trehalose within the cell, supporting efficient utilization of imported or cytoplasmic trehalose. treG – Encodes trehalose-6-phosphate hydrolase, which breaks down trehalose-6-phosphate (an intermediate in trehalose metabolism), aiding in both synthesis and degradation pathways depending on the metabolic context.

Trehalose References