Energy coupling to periplasmic binding protein-dependent transport systems: stoichiometry of ATP hydrolysis during transport in vivo.
AUTOR(ES)
Mimmack, M L
RESUMO
Periplasmic binding protein-dependent transport systems mediate the accumulation of many diverse substrates in prokaryotic cells. Similar transport systems, including the P-glycoprotein responsible for multidrug resistance in human tumors, are also found in eukaryotes. The mechanism by which energy is coupled to the accumulation of substrate by these transport systems has been controversial. In this paper we demonstrate that ATP hydrolysis occurs in vivo concomitantly with transport. These data strongly suggest that ATP hydrolysis directly energizes substrate accumulation by these transport systems. The apparent stoichiometry is one to two molecules of ATP hydrolyzed per molecule of substrate transported.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=298259Documentos Relacionados
- Nucleotide binding by membrane components of bacterial periplasmic binding protein-dependent transport systems.
- Redundancy in Periplasmic Binding Protein-Dependent Transport Systems for Trehalose, Sucrose, and Maltose in Sinorhizobium meliloti
- Possible involvement of lipoic acid in binding protein-dependent transport systems in Escherichia coli.
- Functional exchangeability of the ABC proteins of the periplasmic binding protein-dependent transport systems Ugp and Mal of Escherichia coli.
- Requirements of acetyl phosphate for the binding protein-dependent transport systems in Escherichia coli.