Single transporter for sulfate, selenate, and selenite in Escherichia coli K-12.
A Michaelis-Menten kinetic analysis of the transport of sulfate, selenate, and selenite into Escherichia coli K-12 showed that the three dianions were transported by the same carrier. Km values, used as a measure of the affinity of each ligand for the carrier, showed that sulfate was bound 5 times more tightly than selenate and 37 times more tightly than selenite. The specificity ratio, Vmax/Km, also indicated that sulfate was the preferred ligand. There was little difference in the ratios for selenate and selenite.
D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism*; D007700:Kinetics; D020887:Selenious Acid; D012643:Selenium / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism*; D013462:Sulfur Radioisotopes
D002352:Carrier Proteins; D013431:Sulfates; D013462:Sulfur Radioisotopes; D020887:Selenious Acid; D012643:Selenium