Fructose-1-kinase has pleiotropic roles in Escherichia coli.
J Biol Chem
; 300(6): 107352, 2024 Jun.
Article
em En
| MEDLINE
| ID: mdl-38723750
ABSTRACT
In Escherichia coli, 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 E. coli 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 ΔfruK strain and fruK complementation show that FruK has a broader role in metabolism than fructose catabolism. Since fruK itself is repressed by Cra, these newly-reported events add layers to the dynamic regulation of E. coli's 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.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Escherichia coli
/
Escherichia coli
Idioma:
En
Revista:
J Biol Chem
/
J. biol. chem
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Journal of biological chemistry
Ano de publicação:
2024
Tipo de documento:
Article