Nitrate and nitrite transport in Escherichia coli.

Two polytopic membrane proteins, NarK and NarU, are involved in nitrate and nitrite uptake and nitrite extrusion by Escherichia coli. A third polytopic membrane protein, NirC, functions only in nitrite transport. During exponential growth, the quantity of NarU in membrane fractions was <0.01% of the quantity of NarK. During the stationary phase of growth… CONTINUE READING