HEADER IMMUNE SYSTEM 10-MAR-08 3CHN TITLE Solution structure of human secretory IgA1 COMPND MOL_ID: 2; COMPND 2 MOLECULE: Ig alpha-1 chain C region; COMPND 3 CHAIN: A, B, D, C; EXPDTA SOLUTION SCATTERING DBREF 3CHN A 123 475 UNP P01876 IGHA1_HUMAN 1 353 SEQRES 1 A 108 ASN THR PHE ARG PRO GLU VAL HIS LEU LEU PRO PRO PRO SEQRES 2 A 108 SER GLU GLU LEU ALA LEU ASN GLU LEU VAL THR LEU THR SEQRES 3 A 108 CYS LEU ALA ARG GLY PHE SER PRO LYS ASP VAL LEU VAL SEQRES 4 A 108 ARG TRP LEU GLN GLY SER GLN GLU LEU PRO ARG GLU LYS SEQRES 5 A 108 TYR LEU THR TRP ALA SER ARG GLN GLU PRO SER GLN GLY SEQRES 6 A 108 THR THR THR PHE ALA VAL THR SER ILE LEU ARG VAL ALA SEQRES 7 A 108 ALA GLU ASP TRP LYS LYS GLY ASP THR PHE SER CYS MET SEQRES 8 A 108 VAL GLY HIS GLU ALA LEU PRO LEU ALA PHE THR GLN LYS SEQRES 9 A 108 THR ILE ASP ARG ATOM 1 CA ASN A 346 44.854 29.493 35.267 0.00 0.00 ATOM 2 CA THR A 347 41.396 30.853 34.106 0.00 0.00 ATOM 3 CA PHE A 348 40.297 32.403 30.697 0.00 0.00 ATOM 4 CA ARG A 349 36.883 34.058 29.813 0.00 0.00 ATOM 5 CA PRO A 350 34.806 32.066 27.184 0.00 0.00 ATOM 6 CA GLU A 351 34.052 33.934 23.931 0.00 0.00 ATOM 7 CA VAL A 352 30.429 32.927 23.000 0.00 0.00 ATOM 8 CA HIS A 353 29.364 33.489 19.320 0.00 0.00 ATOM 9 CA LEU A 354 25.924 32.241 18.098 0.00 0.00 ATOM 10 CA LEU A 355 25.817 31.064 14.455 0.00 0.00 ATOM 11 CA PRO A 356 22.534 30.842 12.412 0.00 0.00 ATOM 12 CA PRO A 357 21.971 27.891 9.967 0.00 0.00 ATOM 13 CA PRO A 358 23.626 27.673 6.516 0.00 0.00 ATOM 14 CA SER A 359 21.486 28.717 3.465 0.00 0.00 ATOM 15 CA GLU A 360 21.556 25.082 2.119 0.00 0.00 ATOM 16 CA GLU A 361 20.189 23.644 5.462 0.00 0.00 ATOM 17 CA LEU A 362 16.979 25.729 4.881 0.00 0.00 ATOM 18 CA ALA A 363 16.319 23.243 1.997 0.00 0.00 ATOM 19 CA LEU A 364 15.906 20.740 4.946 0.00 0.00 ATOM 20 CA ASN A 365 12.743 20.642 7.199 0.00 0.00 ATOM 21 CA GLU A 366 12.365 18.865 10.646 0.00 0.00 ATOM 22 CA LEU A 367 15.618 20.189 12.266 0.00 0.00 ATOM 23 CA VAL A 368 17.381 23.589 11.704 0.00 0.00 ATOM 24 CA THR A 369 20.898 23.545 13.053 0.00 0.00 ATOM 25 CA LEU A 370 21.374 26.466 15.544 0.00 0.00 ATOM 26 CA THR A 371 25.046 26.534 16.591 0.00 0.00 ATOM 27 CA CYS A 372 26.858 28.335 19.428 0.00 0.00 ATOM 28 CA LEU A 373 30.685 28.354 19.558 0.00 0.00 ATOM 29 CA ALA A 374 32.262 28.734 23.046 0.00 0.00 ATOM 30 CA ARG A 375 36.010 29.317 22.426 0.00 0.00 ATOM 31 CA GLY A 376 39.258 30.411 24.190 0.00 0.00 ATOM 32 CA PHE A 377 38.093 29.194 27.658 0.00 0.00 ATOM 33 CA SER A 378 40.025 27.572 30.594 0.00 0.00 ATOM 34 CA PRO A 379 39.775 25.438 32.577 0.00 0.00 ATOM 35 CA LYS A 380 37.661 22.936 30.500 0.00 0.00 ATOM 36 CA ASP A 381 35.016 23.119 33.224 0.00 0.00 ATOM 37 CA VAL A 382 31.869 24.689 31.598 0.00 0.00 ATOM 38 CA LEU A 383 28.028 24.305 31.320 0.00 0.00 ATOM 39 CA VAL A 384 26.185 25.238 28.120 0.00 0.00 ATOM 40 CA ARG A 385 22.342 25.168 27.847 0.00 0.00 ATOM 41 CA TRP A 386 19.726 26.450 25.345 0.00 0.00 ATOM 42 CA LEU A 387 16.496 28.450 25.891 0.00 0.00 ATOM 43 CA GLN A 388 13.406 29.249 23.767 0.00 0.00 ATOM 44 CA GLY A 389 12.245 32.945 23.863 0.00 0.00 ATOM 45 CA SER A 390 8.867 32.160 22.144 0.00 0.00 ATOM 46 CA GLN A 391 7.564 29.906 25.033 0.00 0.00 ATOM 47 CA GLU A 392 9.776 31.347 27.899 0.00 0.00 ATOM 48 CA LEU A 393 11.132 27.788 28.526 0.00 0.00 ATOM 49 CA PRO A 394 14.345 25.661 28.347 0.00 0.00 ATOM 50 CA ARG A 395 14.825 23.568 25.154 0.00 0.00 ATOM 51 CA GLU A 396 15.223 19.799 24.567 0.00 0.00 ATOM 52 CA LYS A 397 16.690 18.907 21.142 0.00 0.00 ATOM 53 CA TYR A 398 20.313 19.985 21.693 0.00 0.00 ATOM 54 CA LEU A 399 23.713 18.223 21.852 0.00 0.00 ATOM 55 CA THR A 400 27.138 19.583 23.068 0.00 0.00 ATOM 56 CA TRP A 401 30.537 18.124 21.891 0.00 0.00 ATOM 57 CA ALA A 402 34.184 18.788 23.148 0.00 0.00 ATOM 58 CA SER A 403 37.738 20.013 22.108 0.00 0.00 ATOM 59 CA ARG A 404 40.787 20.683 24.422 0.00 0.00 ATOM 60 CA GLN A 405 43.400 22.561 22.256 0.00 0.00 ATOM 61 CA GLU A 406 47.110 21.659 22.952 0.00 0.00 ATOM 62 CA PRO A 407 49.912 21.663 20.259 0.00 0.00 ATOM 63 CA SER A 408 53.768 21.771 20.803 0.00 0.00 ATOM 64 CA GLN A 409 53.675 25.540 21.720 0.00 0.00 ATOM 65 CA GLY A 410 52.552 27.496 24.860 0.00 0.00 ATOM 66 CA THR A 411 49.025 28.008 23.362 0.00 0.00 ATOM 67 CA THR A 412 46.539 25.778 25.352 0.00 0.00 ATOM 68 CA THR A 413 42.787 26.760 25.877 0.00 0.00 ATOM 69 CA PHE A 414 39.474 24.882 24.986 0.00 0.00 ATOM 70 CA ALA A 415 36.671 25.158 22.395 0.00 0.00 ATOM 71 CA VAL A 416 33.201 23.496 22.102 0.00 0.00 ATOM 72 CA THR A 417 30.267 23.748 19.679 0.00 0.00 ATOM 73 CA SER A 418 26.663 23.224 20.922 0.00 0.00 ATOM 74 CA ILE A 419 23.967 22.198 18.394 0.00 0.00 ATOM 75 CA LEU A 420 20.245 23.103 18.979 0.00 0.00 ATOM 76 CA ARG A 421 18.062 21.469 16.306 0.00 0.00 ATOM 77 CA VAL A 422 14.667 23.228 15.562 0.00 0.00 ATOM 78 CA ALA A 423 11.767 23.025 13.047 0.00 0.00 ATOM 79 CA ALA A 424 12.523 25.267 9.956 0.00 0.00 ATOM 80 CA GLU A 425 9.181 27.095 10.600 0.00 0.00 ATOM 81 CA ASP A 426 9.846 28.387 14.219 0.00 0.00 ATOM 82 CA TRP A 427 13.177 29.996 13.154 0.00 0.00 ATOM 83 CA LYS A 428 11.220 31.726 10.270 0.00 0.00 ATOM 84 CA LYS A 429 8.342 32.641 12.698 0.00 0.00 ATOM 85 CA GLY A 430 11.035 35.018 14.132 0.00 0.00 ATOM 86 CA ASP A 431 11.788 33.136 17.366 0.00 0.00 ATOM 87 CA THR A 432 14.718 34.135 19.617 0.00 0.00 ATOM 88 CA PHE A 433 16.811 31.163 20.861 0.00 0.00 ATOM 89 CA SER A 434 19.595 31.814 23.430 0.00 0.00 ATOM 90 CA CYS A 435 22.730 29.829 24.279 0.00 0.00 ATOM 91 CA MET A 436 23.529 30.236 28.037 0.00 0.00 ATOM 92 CA VAL A 437 27.187 29.582 29.038 0.00 0.00 ATOM 93 CA GLY A 438 28.298 29.172 32.694 0.00 0.00 ATOM 94 CA HIS A 439 32.030 29.303 33.475 0.00 0.00 ATOM 95 CA GLU A 440 34.482 30.238 36.339 0.00 0.00 ATOM 96 CA ALA A 441 35.777 33.352 34.428 0.00 0.00 ATOM 97 CA LEU A 442 32.381 34.788 33.262 0.00 0.00 ATOM 98 CA PRO A 443 31.239 38.144 34.882 0.00 0.00 ATOM 99 CA LEU A 444 28.364 36.739 37.040 0.00 0.00 ATOM 100 CA ALA A 445 29.529 33.118 36.305 0.00 0.00 ATOM 101 CA PHE A 446 26.902 33.346 33.522 0.00 0.00 ATOM 102 CA THR A 447 26.571 34.861 30.031 0.00 0.00 ATOM 103 CA GLN A 448 23.844 34.370 27.395 0.00 0.00 ATOM 104 CA LYS A 449 24.158 35.158 23.628 0.00 0.00 ATOM 105 CA THR A 450 20.983 35.207 21.453 0.00 0.00 ATOM 106 CA ILE A 451 19.985 34.032 17.889 0.00 0.00 ATOM 107 CA ASP A 452 16.914 35.037 15.797 0.00 0.00 ATOM 108 CA ARG A 453 15.866 35.281 12.073 0.00 0.00 TER