0 9 Isolation isolation NN 10 12 of of IN 13 14 a a DT 15 24 candidate candidate NN 25 44 repressor/activator repressor/activator NN 44 45 , , , 46 51 NF-E1 NF-E1 NNP 52 53 ( ( ( 53 57 YY-1 YY-1 NNP 57 58 , , , 59 64 delta delta NN 64 65 ) ) ) 65 66 , , , 67 71 that that WDT 72 77 binds bind VBZ 78 80 to to TO 81 84 the the DT 85 99 immunoglobulin immunoglobulin NN 100 105 kappa kappa NN 106 107 3 3 CD 107 108 ’ ' SYM 109 117 enhancer enhancer NN 118 121 and and CC 122 125 the the DT 126 140 immunoglobulin immunoglobulin NN 141 152 heavy-chain heavy-chain JJ 153 155 mu mu NN 156 158 E1 e1 NN 159 163 site site NN 163 164 . . . 166 168 We we PRP 169 173 have have VBP 174 184 determined determine VBN 185 189 that that IN 190 193 the the DT 194 207 developmental developmental JJ 208 215 control control NN 216 218 of of IN 219 233 immunoglobulin immunoglobulin NN 234 239 kappa kappa NN 240 241 3 3 CD 241 242 ’ ' SYM 243 251 enhancer enhancer NN 252 253 ( ( ( 253 258 kappa kappa NN 259 261 E3 E3 NNP 261 262 ’ ' '' 262 263 ) ) ) 264 272 activity activity NN 273 275 is be VBZ 276 279 the the DT 280 286 result result NN 287 289 of of IN 290 293 the the DT 294 302 combined combined JJ 303 312 influence influence NN 313 315 of of IN 316 325 positive- positive- NN 326 329 and and CC 330 345 negative-acting negative-acting JJ 346 354 elements element NNS 354 355 . . . 356 358 We we PRP 359 363 show show VBP 364 368 that that IN 369 370 a a DT 371 378 central central JJ 379 383 core core NN 384 386 in in IN 387 390 the the DT 391 396 kappa kappa NN 397 399 E3 e3 NN 399 400 ’ ' '' 401 409 enhancer enhancer NN 410 412 is be VBZ 413 419 active active JJ 420 422 at at IN 423 426 the the DT 427 437 pre-B-cell pre-b-cell JJ 438 443 stage stage NN 444 447 but but CC 448 450 is be VBZ 451 460 repressed repress VBN 461 463 by by IN 464 472 flanking flank VBG 473 488 negative-acting negative-acting JJ 489 497 elements element NNS 497 498 . . . 499 502 The the DT 503 518 negative-acting negative-acting JJ 519 528 sequences sequence NNS 529 536 repress repress VBP 537 545 enhancer enhancer NN 546 554 activity activity NN 555 557 in in IN 558 559 a a DT 560 569 position- position- NN 570 573 and and CC 574 597 orientation-independent orientation-independent JJ 598 604 manner manner NN 605 607 at at IN 608 611 the the DT 612 622 pre-B-cell pre-b-cell JJ 623 628 stage stage NN 628 629 . . . 630 632 We we PRP 633 637 have have VBP 638 646 isolated isolate VBN 647 648 a a DT 649 654 human human JJ 655 659 cDNA cdna NN 660 665 clone clone NN 666 674 encoding encode VBG 675 676 a a DT 677 681 zinc zinc NN 682 688 finger finger NN 689 696 protein protein NN 697 698 ( ( ( 698 703 NF-E1 NF-E1 NNP 703 704 ) ) ) 705 709 that that WDT 710 715 binds bind VBZ 716 718 to to TO 719 722 the the DT 723 738 negative-acting negative-acting JJ 739 746 segment segment NN 747 749 of of IN 750 753 the the DT 754 759 kappa kappa NN 760 762 E3 e3 NN 762 763 ’ ' '' 764 772 enhancer enhancer NN 772 773 . . . 774 778 This this DT 779 786 protein protein NN 787 791 also also RB 792 797 binds bind VBZ 798 800 to to TO 801 804 the the DT 805 819 immunoglobulin immunoglobulin NN 820 831 heavy-chain heavy-chain JJ 832 840 enhancer enhancer NN 841 843 mu mu NN 844 846 E1 e1 NN 847 851 site site NN 851 852 . . . 853 858 NF-E1 NF-E1 NNP 859 861 is be VBZ 862 869 encoded encode VBN 870 872 by by IN 873 876 the the DT 877 881 same same JJ 882 886 gene gene NN 887 889 as as IN 890 893 the the DT 894 898 YY-1 yy-1 NN 899 906 protein protein NN 906 907 , , , 908 913 which which WDT 914 919 binds bind VBZ 920 922 to to TO 923 926 the the DT 927 943 adeno-associated adeno-associated JJ 944 949 virus virus NN 950 952 P5 p5 NN 953 961 promoter promoter NN 961 962 . . . 963 968 NF-E1 NF-E1 NNP 969 971 is be VBZ 972 976 also also RB 977 980 the the DT 981 986 human human JJ 987 996 homologue homologue NN 997 999 of of IN 1000 1003 the the DT 1004 1009 mouse mouse NN 1010 1015 delta delta NN 1016 1023 protein protein NN 1023 1024 , , , 1025 1030 which which WDT 1031 1036 binds bind VBZ 1037 1039 to to TO 1040 1049 ribosomal ribosomal JJ 1050 1057 protein protein NN 1058 1062 gene gene NN 1063 1072 promoters promoter NNS 1072 1073 . . . 1074 1077 The the DT 1078 1087 predicted predict VBN 1088 1093 amino amino NN 1094 1098 acid acid NN 1099 1107 sequence sequence NN 1108 1110 of of IN 1111 1115 this this DT 1116 1123 protein protein NN 1124 1132 contains contain VBZ 1133 1141 features feature NNS 1142 1156 characteristic characteristic JJ 1157 1159 of of IN 1160 1175 transcriptional transcriptional JJ 1176 1186 activators activator NNS 1187 1189 as as RB 1190 1194 well well RB 1195 1197 as as IN 1198 1213 transcriptional transcriptional JJ 1214 1224 repressors repressor NNS 1224 1225 . . . 1226 1240 Cotransfection cotransfection NN 1241 1248 studies study NNS 1249 1253 with with IN 1254 1258 this this DT 1259 1263 cDNA cDNA NNP 1264 1272 indicate indicate VBP 1273 1277 that that IN 1278 1280 it it PRP 1281 1284 can can MD 1285 1292 repress repress VB 1293 1298 basal basal JJ 1299 1307 promoter promoter NN 1308 1316 activity activity NN 1316 1317 . . . 1318 1321 The the DT 1322 1330 apparent apparent JJ 1331 1335 dual dual JJ 1336 1344 function function NN 1345 1347 of of IN 1348 1352 this this DT 1353 1360 protein protein NN 1361 1363 is be VBZ 1364 1373 discussed discuss VBN 1373 1374 . . .