0 3 Two two CD 4 12 distinct distinct JJ 13 26 transcription transcription NN 27 34 factors factor NNS 35 39 that that WDT 40 44 bind bind VBP 45 48 the the DT 49 63 immunoglobulin immunoglobulin NN 64 72 enhancer enhancer NN 73 86 microE5/kappa microe5/kappa NN 87 88 2 2 CD 89 94 motif motif NN 94 95 . . . 97 105 Activity activity NN 106 108 of of IN 109 112 the the DT 113 127 immunoglobulin immunoglobulin NN 128 133 heavy heavy NN 134 137 and and CC 138 143 kappa kappa NN 144 149 light light JJ 150 155 chain chain NN 156 160 gene gene NN 161 170 enhancers enhancer NNS 171 178 depends depend VBZ 179 181 on on IN 182 183 a a DT 184 191 complex complex JJ 192 201 interplay interplay NN 202 204 of of IN 205 215 ubiquitous ubiquitous JJ 216 219 and and CC 220 235 developmentally developmentally RB 236 245 regulated regulate VBN 246 254 proteins protein NNS 254 255 . . . 256 259 Two two CD 260 273 complementary complementary JJ 274 278 DNAs dna NNS 279 283 were be VBD 284 292 isolated isolate VBN 293 297 that that IN 298 304 encode encode NN 305 313 proteins protein NNS 313 314 , , , 315 322 denoted denote VBN 323 328 ITF-1 itf-1 NN 329 332 and and CC 333 338 ITF-2 itf-2 NN 338 339 , , , 340 344 that that WDT 345 348 are be VBP 349 358 expressed express VBN 359 361 in in IN 362 363 a a DT 364 371 variety variety NN 372 374 of of IN 375 379 cell cell NN 380 385 types type NNS 386 389 and and CC 390 394 bind bind VBP 395 398 the the DT 399 412 microE5/kappa microe5/kappa NN 413 414 2 2 CD 415 420 motif motif NN 421 426 found find VBN 427 429 in in IN 430 434 both both CC 435 440 heavy heavy JJ 441 444 and and CC 445 450 kappa kappa NN 451 456 light light JJ 457 462 chain chain NN 463 472 enhancers enhancer NNS 472 473 . . . 474 477 The the DT 478 491 complementary complementary JJ 492 496 DNAs dna NNS 497 500 are be VBP 501 504 the the DT 505 513 products product NNS 514 516 of of IN 517 525 distinct distinct JJ 526 531 genes gene NNS 531 532 , , , 533 536 yet yet CC 537 541 both both CC 542 547 ITF-1 itf-1 NN 548 551 and and CC 552 557 ITF-2 itf-2 NN 558 561 are be VBP 562 574 structurally structurally RB 575 578 and and CC 579 591 functionally functionally RB 592 599 similar similar JJ 599 600 . . . 601 604 The the DT 605 608 two two CD 609 617 proteins protein NNS 618 626 interact interact VBP 627 631 with with IN 632 635 one one CD 636 643 another another DT 644 651 through through IN 652 657 their their PRP$ 658 666 putative putative JJ 667 683 helix-loop-helix helix-loop-helix JJ 684 690 motifs motif NNS 691 694 and and CC 695 699 each each DT 700 709 possesses possess VBZ 710 711 a a DT 712 720 distinct distinct JJ 721 727 domain domain NN 728 732 that that WDT 733 741 dictates dictate VBZ 742 755 transcription transcription NN 756 766 activation activation NN 766 767 . . .