0 3 The the DT 4 14 Legionella Legionella NNP 15 26 pneumophila pneumophila NN 27 31 rpoS rpos NN 32 36 gene gene NN 37 39 is be VBZ 40 48 required require VBN 49 52 for for IN 53 59 growth growth NN 60 66 within within IN 67 79 Acanthamoeba Acanthamoeba NNP 80 91 castellanii castellanii NN 91 92 . . . 94 96 To to TO 97 108 investigate investigate VB 109 119 regulatory regulatory JJ 120 128 networks network NNS 129 131 in in IN 132 142 Legionella Legionella NNP 143 154 pneumophila pneumophila NN 154 155 , , , 156 159 the the DT 160 164 gene gene NN 165 173 encoding encode VBG 174 177 the the DT 178 185 homolog homolog NN 186 188 of of IN 189 192 the the DT 193 204 Escherichia escherichia FW 205 209 coli coli FW 210 216 stress stress NN 217 220 and and CC 221 237 stationary-phase stationary-phase NN 238 243 sigma sigma NN 244 250 factor factor NN 251 255 RpoS rpos NN 256 259 was be VBD 260 270 identified identify VBN 271 273 by by IN 274 289 complementation complementation NN 290 292 of of IN 293 295 an an DT 296 298 E. e. FW 299 303 coli coli FW 304 308 rpoS rpos NN 309 317 mutation mutation NN 317 318 . . . 319 321 An an DT 322 326 open open JJ 327 334 reading reading NN 335 340 frame frame NN 341 345 that that WDT 346 348 is be VBZ 349 362 approximately approximately RB 363 365 60 60 CD 365 366 % % NN 367 376 identical identical JJ 377 379 to to TO 380 383 the the DT 384 386 E. e. FW 387 391 coli coli FW 392 396 rpoS rpos NN 397 401 gene gene NN 402 405 was be VBD 406 416 identified identify VBN 416 417 . . . 418 425 Western western NN 426 430 blot blot NN 431 439 analysis analysis NN 440 446 showed show VBD 447 451 that that IN 452 455 the the DT 456 461 level level NN 462 464 of of IN 465 467 L. l. FW 468 479 pneumophila pneumophila FW 480 484 RpoS rpos NN 485 494 increased increase VBD 495 497 in in IN 498 508 stationary stationary JJ 509 514 phase phase NN 514 515 . . . 516 518 An an DT 519 528 insertion insertion NN 529 537 mutation mutation NN 538 541 was be VBD 542 553 constructed construct VBN 554 556 in in IN 557 560 the the DT 561 565 rpoS rpos NN 566 570 gene gene NN 571 573 on on IN 574 577 the the DT 578 588 chromosome chromosome NN 589 591 of of IN 592 594 L. l. FW 595 606 pneumophila pneumophila FW 606 607 , , , 608 611 and and CC 612 615 the the DT 616 623 ability ability NN 624 626 of of IN 627 631 this this DT 632 638 mutant mutant JJ 639 645 strain strain NN 646 648 to to TO 649 656 survive survive VB 657 664 various various JJ 665 671 stress stress NN 672 682 conditions condition NNS 683 686 was be VBD 687 694 assayed assay VBN 695 698 and and CC 699 707 compared compare VBN 708 712 with with IN 713 720 results result NNS 721 724 for for IN 725 728 the the DT 729 738 wild-type wild-type JJ 739 745 strain strain NN 745 746 . . . 747 751 Both both CC 752 755 the the DT 756 762 mutant mutant JJ 763 766 and and CC 767 776 wild-type wild-type JJ 777 784 strains strain NNS 785 789 were be VBD 790 794 more more RBR 795 804 resistant resistant JJ 805 807 to to TO 808 814 stress stress NN 815 819 when when WRB 820 822 in in IN 823 833 stationary stationary JJ 834 839 phase phase NN 840 844 than than IN 845 849 when when WRB 850 852 in in IN 853 856 the the DT 857 868 logarithmic logarithmic JJ 869 874 phase phase NN 875 877 of of IN 878 884 growth growth NN 884 885 . . . 886 890 This this DT 891 898 finding finding NN 899 908 indicates indicate VBZ 909 913 that that IN 914 916 L. l. FW 917 928 pneumophila pneumophila FW 929 933 RpoS RpoS NNP 934 936 is be VBZ 937 940 not not RB 941 949 required require VBN 950 953 for for IN 954 955 a a DT 956 982 stationary-phase-dependent stationary-phase-dependent JJ 983 993 resistance resistance NN 994 996 to to TO 997 1003 stress stress NN 1003 1004 . . . 1005 1013 Although although IN 1014 1017 the the DT 1018 1024 mutant mutant JJ 1025 1031 strain strain NN 1032 1035 was be VBD 1036 1040 able able JJ 1041 1043 to to TO 1044 1048 kill kill VB 1049 1055 HL-60- hl-60- NN 1056 1059 and and CC 1060 1073 THP-1-derived thp-1-derived JJ 1074 1085 macrophages macrophage NNS 1085 1086 , , , 1087 1089 it it PRP 1090 1095 could could MD 1096 1099 not not RB 1100 1109 replicate replicate VB 1110 1116 within within IN 1117 1118 a a DT 1119 1128 protozoan protozoan NN 1129 1133 host host NN 1133 1134 , , , 1135 1147 Acanthamoeba acanthamoeba NN 1148 1159 castellanii castellanii NN 1159 1160 . . . 1161 1166 These these DT 1167 1171 data datum NNS 1172 1179 suggest suggest VBP 1180 1184 that that IN 1185 1187 L. l. FW 1188 1199 pneumophila pneumophila FW 1200 1209 possesses possess VBZ 1210 1211 a a DT 1212 1218 growth growth NN 1219 1234 phase-dependent phase-dependent JJ 1235 1245 resistance resistance NN 1246 1248 to to TO 1249 1255 stress stress NN 1256 1260 that that WDT 1261 1263 is be VBZ 1264 1275 independent independent JJ 1276 1278 of of IN 1279 1283 RpoS RpoS NNP 1284 1291 control control NN 1292 1295 and and CC 1296 1300 that that IN 1301 1305 RpoS RpoS NNP 1306 1312 likely likely RB 1313 1322 regulates regulate VBZ 1323 1328 genes gene NNS 1329 1333 that that WDT 1334 1340 enable enable VBP 1341 1343 it it PRP 1344 1346 to to TO 1347 1354 survive survive VB 1355 1357 in in IN 1358 1361 the the DT 1362 1373 environment environment NN 1374 1380 within within IN 1381 1389 protozoa protozoa NN 1389 1390 . . . 1391 1394 Our our PRP$ 1395 1399 data datum NNS 1400 1408 indicate indicate VBP 1409 1413 that that IN 1414 1417 the the DT 1418 1422 role role NN 1423 1425 of of IN 1426 1430 rpoS rpos NN 1431 1433 in in IN 1434 1436 L. l. FW 1437 1448 pneumophila pneumophila FW 1449 1451 is be VBZ 1452 1456 very very RB 1457 1466 different different JJ 1467 1471 from from IN 1472 1476 what what WP 1477 1480 has have VBZ 1481 1491 previously previously RB 1492 1496 been be VBN 1497 1505 reported report VBN 1506 1509 for for IN 1510 1512 E. e. FW 1513 1517 coli coli FW 1518 1522 rpoS rpos NN 1522 1523 . . .