Figure 4

Residues essential for activity of the two fatty acid Gate-domains. Leucine 316 of isoform 2 (F-Gate) was changed to a histidine in the normal F-Gate form to generate the mutant H³¹⁶ - F³¹⁹ and in the mutant (F-to-Y)³¹⁹ to generate the double mutant H³¹⁶ - Y³¹⁹. Similarly, histidine 316 of isoform 1 (Y-Gate) was changed to a leucine in the normal Y-Gate form to generate the mutant L³¹⁶ - Y³¹⁹, and in the mutant (Y to F)³¹⁹ to generate the double mutant L³¹⁶ - F³¹⁹. Activity measurements were performed with 5 μM (¹⁴C)-C_18:1-OH as described in legend of Figure 2. Activity rate of the normal forms (either the F-Gate or the Y-Gate; filled bars) was set at 100% and values obtained with the corresponding mutated forms were calculated relative to these. Data obtained with ΔN-Y-Gate construct and full-length F-Gate isoform are presented (see legend Figure 3). Average and the standard deviation of 3 different experiments are shown.