Phosphatidylglycerol directs binding and inhibitory action of EIIAGlc protein on the maltose transporter.
J Biol Chem
; 288(33): 23666-74, 2013 Aug 16.
Article
em En
| MEDLINE
| ID: mdl-23821551
ABSTRACT
The signal-transducing protein EIIA(Glc) belongs to the phosphoenolpyruvate carbohydrate phosphotransferase system. In its dephosphorylated state, EIIA(Glc) is a negative regulator for several permeases, including the maltose transporter MalFGK2. How EIIA(Glc) is targeted to the membrane, how it interacts with the transporter, and how it inhibits sugar uptake remain obscure. We show here that acidic phospholipids together with the N-terminal tail of EIIA(Glc) are essential for the high affinity binding of the protein to the transporter. Using protein docking prediction and chemical cross-linking, we demonstrate that EIIA(Glc) binds to the MalK dimer, interacting with both the nucleotide-binding and the C-terminal regulatory domains. Dissection of the ATPase cycle reveals that EIIA(Glc) does not affect the binding of ATP but rather inhibits the capacity of MalK to cleave ATP. We propose a mechanism of maltose transport inhibition by this central amphitropic regulatory protein.
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MEDLINE
Assunto principal:
Fosfatidilgliceróis
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Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato
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Transportadores de Cassetes de Ligação de ATP
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Proteínas de Escherichia coli
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Escherichia coli
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article