5 100 2 prpR JE4766 JE4593 PrpR -LRB- WT -RRB- PrpR -LRB- DA domain -RRB- c 940 ± 45 62 prpR234 prpR235 prpR236 JE6634 JE6635 180 ± 26 260 ± 26 19 28 12 17 F129L E50K prpR237 prpR238 JE6636 JE6637 190 ± 4 980 ± 15 20 13 65 D37N A162T 104 S33R F49L prpR239 prpR240 JE6638 JE6639 580 ± 22 415 ± 21 62 44 38 28 E172G F49S prpR241 prpR242 JE6672 JE6673 65 ± 4 170 ± 9 7 4 18 11 S33N E142K prpR243 prpR244 JE6674 JE6675 500 ± 4 530 ± 77 53 56 33 35 R24S prpR245 prpR246 JE6865 JE6762 490 ± 10 85 ± 12 52 9 32 6 Y180H L47P S21P prpR247 prpR248 JE6763 JE6764 360 ± 22 90 ± 5 38 24 9 6 R24H G104E prpR249 prpR250 JE6765 JE6766 350 ± 47 70 ± 14 37 23 7 5 K81H F178C prpR251 prpR252 JE6767 JE6768 350 ± 12 570 ± 13 37 23 61 36 38 23 340 ± 34 JE6769 D31G prpR253 PrpR is different from other well-studied members of this family of activators , such as XylR and DmpR , in which the region linking the sensing and catalytic domains contains a coiled-coil structure that is important for controlling binding of the effector molecule and activation of the protein .