Journal Article

Fructose-1-kinase has pleiotropic roles in Escherichia coli

Hardwidge, Philip R, Hefty, P Scott, Sreenivasan, Shwetha, Meinhardt, Sarah, Bose, Jeffrey L, Menjivar, Cindy, Fenton, Aron W, Bird, Cole L, Swint-Kruse, Liskin, O'Neil, Pierce T, Weeramange, Chamitha, El Qaidi, Samir, Harrison, Kelly S

2023

Overview

In , the master transcription regulator Catabolite Repressor Activator (Cra) regulates >100 genes in central metabolism. Cra binding to DNA is allosterically regulated by binding to fructose-1-phosphate (F-1-P), but the only documented source of F-1-P is from the concurrent import and phosphorylation of exogenous fructose. Thus, many have proposed that fructose-1,6-bisphosphate (F-1,6-BP) is also a physiological regulatory ligand. However, the role of F-1,6-BP has been widely debated. Here, we report that the enzyme fructose-1-kinase (FruK) can carry out its \"reverse\" reaction under physiological substrate concentrations to generate F-1-P from F-1,6-BP. We further show that FruK directly binds Cra with nanomolar affinity and forms higher order, heterocomplexes. Growth assays with a Δ strain and complementation show that FruK has a broader role in metabolism than fructose catabolism. The Δ strain also alters biofilm formation. Since itself is repressed by Cra, these newly-reported events add layers to the dynamic regulation of central metabolism that occur in response to changing nutrients. These findings might have wide-spread relevance to other γ-proteobacteria, which conserve both Cra and FruK.

• Publisher: Cold Spring Harbor Laboratory Press,Cold Spring Harbor Laboratory
• Subject: Biofilms / Complementation / E coli / Escherichia coli / Fructose-1,6-bisphosphate / Kinases / Metabolism / Microbiology / Phosphorylation / Physiology