[http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=6998957 Characterization of two genetically separable inorganic phosphate transport systems in Escherichia coli, JB 1980 (G R Willsky and M H Malamy)]
high affinity-low velocity Pst (phosphate specific transport) system have a Km of 0.43 +/- 0.2 microM Pi and a Vmax of 15.9 +/- 0.3 nmol of Pi
low affinity-high velocity Pit (Pi transport) system have a Km of 38.2 +/- 0.4 microM and a Vmax of 55 +/- 1.9 nmol of Pi
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