0 10 Activation Activation NNP 11 13 of of IN 14 27 transcription transcription NN 28 30 by by IN 31 38 binding binding NN 39 41 of of IN 42 47 NF-E1 NF-E1 NNP 48 49 ( ( ( 49 52 YY1 YY1 NNP 52 53 ) ) ) 54 56 to to TO 57 58 a a DT 59 64 newly newly RB 65 75 identified identify VBN 76 83 element element NN 84 86 in in IN 87 90 the the DT 91 96 first first JJ 97 101 exon exon NN 102 104 of of IN 105 108 the the DT 109 114 human human JJ 115 117 DR dr NN 118 123 alpha alpha NN 124 128 gene gene NN 128 129 . . . 131 132 A a DT 133 143 previously previously RB 144 156 unrecognized unrecognized JJ 157 164 element element NN 164 165 , , , 166 173 located located JJ 174 184 downstream downstream RB 185 187 of of IN 188 191 the the DT 192 197 start start NN 198 202 site site NN 203 205 of of IN 206 219 transcription transcription NN 220 222 in in IN 223 226 the the DT 227 232 first first JJ 233 237 exon exon NN 238 240 of of IN 241 244 the the DT 245 247 DR DR NNP 248 253 alpha alpha NN 254 258 gene gene NN 258 259 , , , 260 263 has have VBZ 264 268 been be VBN 269 276 defined define VBN 277 281 that that WDT 282 290 enhances enhance VBZ 291 299 promoter promoter NN 300 308 activity activity NN 309 311 up up IN 312 314 to to TO 315 324 eightfold eightfold VB 325 327 in in IN 328 329 a a DT 330 348 position-dependent position-dependent JJ 349 355 manner manner NN 355 356 . . . 357 366 Mutations mutation NNS 367 369 in in IN 370 374 this this DT 375 386 DNA-binding dna-binding JJ 387 391 site site NN 392 401 abolished abolish VBD 402 409 binding binding NN 410 412 of of IN 413 414 a a DT 415 422 nuclear nuclear JJ 423 429 factor factor NN 430 432 in in IN 433 438 human human JJ 439 440 B B NNP 441 445 cell cell NN 446 453 nuclear nuclear JJ 454 461 extract extract NN 462 465 and and CC 466 475 decreased decrease VBD 476 479 the the DT 480 488 activity activity NN 489 491 of of IN 492 495 the the DT 496 498 DR DR NNP 499 504 alpha alpha NN 505 513 promoter promoter NN 514 516 to to TO 517 518 a a DT 519 524 basal basal JJ 525 530 level level NN 530 531 . . . 532 543 Significant significant JJ 544 552 sequence sequence NN 553 561 homology homology NN 562 564 of of IN 565 569 this this DT 570 577 element element NN 578 581 was be VBD 582 587 found find VBN 588 590 in in IN 591 594 the the DT 595 598 DNA dna NN 599 601 of of IN 602 605 the the DT 606 608 DR DR NNP 609 613 beta beta NN 613 614 , , , 615 617 DP DP NNP 618 623 alpha alpha NN 624 627 and and CC 628 633 -beta -beta NN 633 634 , , , 635 638 and and CC 639 641 DQ DQ NNP 642 647 alpha alpha NN 648 653 genes gene NNS 653 654 , , , 655 661 always always RB 662 669 located located JJ 670 680 downstream downstream RB 681 683 of of IN 684 687 the the DT 688 703 transcriptional transcriptional JJ 704 709 start start NN 710 714 site site NN 714 715 . . . 716 719 The the DT 720 727 nuclear nuclear JJ 728 734 factor factor NN 735 740 binds bind VBZ 741 743 to to TO 744 747 the the DT 748 750 DR DR NNP 751 756 alpha alpha NN 757 760 and and CC 761 763 DP DP NNP 764 769 alpha alpha NN 770 777 element element NN 778 781 but but CC 782 785 not not RB 786 788 to to TO 789 792 the the DT 793 800 element element NN 801 803 in in IN 804 807 the the DT 808 810 DQ DQ NNP 811 816 alpha alpha NN 817 821 gene gene NN 821 822 . . . 823 825 It it PRP 826 829 was be VBD 830 840 identified identify VBN 841 843 as as IN 844 849 NF-E1 NF-E1 NNP 850 851 ( ( ( 851 854 YY1 YY1 NNP 854 855 ) ) ) 855 856 . . . 857 861 This this DT 862 869 protein protein NN 869 870 , , , 871 881 previously previously RB 882 892 identified identify VBN 893 895 by by IN 896 899 its its PRP$ 900 907 binding binding NN 908 910 to to TO 911 914 the the DT 915 917 Ig Ig NNP 918 923 kappa kappa NN 924 925 3 3 CD 925 926 ’ ' SYM 927 935 enhancer enhancer NN 936 939 and and CC 940 943 the the DT 944 946 Ig Ig NNP 947 952 heavy heavy JJ 953 958 chain chain NN 959 961 mu mu NN 962 964 E1 e1 NN 965 969 site site NN 969 970 , , , 971 975 thus thus RB 976 980 also also RB 981 988 appears appear VBZ 989 991 to to TO 992 994 be be VB 995 1000 quite quite RB 1001 1010 important important JJ 1011 1013 in in IN 1014 1017 the the DT 1018 1028 regulation regulation NN 1029 1031 of of IN 1032 1035 MHC MHC NNP 1036 1041 class class NN 1042 1044 II ii CD 1045 1049 gene gene NN 1050 1060 expression expression NN 1060 1061 . . .