Inhibition by Thiamine Phosphates of Thiamine Uptake in Escherichia coli

The uptake of thiamine in Escherichia coli was inhibited by thiamine phosphates. It was also demonstrated that the binding of thiamine to thiamine-binding protein, which is thought as a functional component in the transport system of thiamine, is markedly inhibited by thiamine phosphates.The possibility that thiamine and thiamine phosphates share a common transport system in Escherichia coli is discussed.