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 B 123 475 UNP P01876 IGHA1_HUMAN 1 353 SEQRES 1 B 108 ASN THR PHE ARG PRO GLU VAL HIS LEU LEU PRO PRO PRO SEQRES 2 B 108 SER GLU GLU LEU ALA LEU ASN GLU LEU VAL THR LEU THR SEQRES 3 B 108 CYS LEU ALA ARG GLY PHE SER PRO LYS ASP VAL LEU VAL SEQRES 4 B 108 ARG TRP LEU GLN GLY SER GLN GLU LEU PRO ARG GLU LYS SEQRES 5 B 108 TYR LEU THR TRP ALA SER ARG GLN GLU PRO SER GLN GLY SEQRES 6 B 108 THR THR THR PHE ALA VAL THR SER ILE LEU ARG VAL ALA SEQRES 7 B 108 ALA GLU ASP TRP LYS LYS GLY ASP THR PHE SER CYS MET SEQRES 8 B 108 VAL GLY HIS GLU ALA LEU PRO LEU ALA PHE THR GLN LYS SEQRES 9 B 108 THR ILE ASP ARG ATOM 1 CA ASN B 346 24.870 0.722 8.397 0.00 0.00 ATOM 2 CA THR B 347 26.243 3.767 6.399 0.00 0.00 ATOM 3 CA PHE B 348 24.787 7.359 5.938 0.00 0.00 ATOM 4 CA ARG B 349 26.098 10.185 3.600 0.00 0.00 ATOM 5 CA PRO B 350 27.511 13.276 5.513 0.00 0.00 ATOM 6 CA GLU B 351 25.709 16.590 4.833 0.00 0.00 ATOM 7 CA VAL B 352 28.507 19.264 4.711 0.00 0.00 ATOM 8 CA HIS B 353 27.412 22.947 5.199 0.00 0.00 ATOM 9 CA LEU B 354 30.071 25.728 5.459 0.00 0.00 ATOM 10 CA LEU B 355 29.164 28.644 7.771 0.00 0.00 ATOM 11 CA PRO B 356 30.826 32.130 7.515 0.00 0.00 ATOM 12 CA PRO B 357 31.677 34.113 10.731 0.00 0.00 ATOM 13 CA PRO B 358 29.054 35.994 12.798 0.00 0.00 ATOM 14 CA SER B 359 28.787 39.817 12.250 0.00 0.00 ATOM 15 CA GLU B 360 29.992 40.462 15.879 0.00 0.00 ATOM 16 CA GLU B 361 33.196 38.318 15.371 0.00 0.00 ATOM 17 CA LEU B 362 34.272 40.832 12.628 0.00 0.00 ATOM 18 CA ALA B 363 34.766 43.281 15.577 0.00 0.00 ATOM 19 CA LEU B 364 37.628 40.801 16.472 0.00 0.00 ATOM 20 CA ASN B 365 41.013 40.710 14.564 0.00 0.00 ATOM 21 CA GLU B 366 43.696 37.888 14.669 0.00 0.00 ATOM 22 CA LEU B 367 41.309 34.892 14.132 0.00 0.00 ATOM 23 CA VAL B 368 38.029 34.760 12.081 0.00 0.00 ATOM 24 CA THR B 369 36.023 31.680 12.908 0.00 0.00 ATOM 25 CA LEU B 370 35.273 29.705 9.668 0.00 0.00 ATOM 26 CA THR B 371 32.964 26.799 10.567 0.00 0.00 ATOM 27 CA CYS B 372 31.940 23.665 8.644 0.00 0.00 ATOM 28 CA LEU B 373 29.138 21.420 9.982 0.00 0.00 ATOM 29 CA ALA B 374 29.294 17.717 8.945 0.00 0.00 ATOM 30 CA ARG B 375 25.939 16.199 10.050 0.00 0.00 ATOM 31 CA GLY B 376 23.739 13.058 9.653 0.00 0.00 ATOM 32 CA PHE B 377 26.734 10.723 8.983 0.00 0.00 ATOM 33 CA SER B 378 27.398 7.046 9.990 0.00 0.00 ATOM 34 CA PRO B 379 29.530 5.311 10.988 0.00 0.00 ATOM 35 CA LYS B 380 31.467 7.910 13.117 0.00 0.00 ATOM 36 CA ASP B 381 34.527 7.175 10.988 0.00 0.00 ATOM 37 CA VAL B 382 35.362 10.450 9.094 0.00 0.00 ATOM 38 CA LEU B 383 38.292 12.784 8.118 0.00 0.00 ATOM 39 CA VAL B 384 37.795 16.549 7.829 0.00 0.00 ATOM 40 CA ARG B 385 40.568 18.916 6.582 0.00 0.00 ATOM 41 CA TRP B 386 40.776 22.580 5.454 0.00 0.00 ATOM 42 CA LEU B 387 42.399 24.171 2.363 0.00 0.00 ATOM 43 CA GLN B 388 43.365 27.734 1.333 0.00 0.00 ATOM 44 CA GLY B 389 42.395 28.732 -2.283 0.00 0.00 ATOM 45 CA SER B 390 44.556 31.942 -2.215 0.00 0.00 ATOM 46 CA GLN B 391 47.927 30.039 -1.835 0.00 0.00 ATOM 47 CA GLU B 392 46.800 26.616 -3.316 0.00 0.00 ATOM 48 CA LEU B 393 47.871 24.933 -0.012 0.00 0.00 ATOM 49 CA PRO B 394 46.483 23.034 3.048 0.00 0.00 ATOM 50 CA ARG B 395 45.799 25.147 6.191 0.00 0.00 ATOM 51 CA GLU B 396 47.158 24.973 9.772 0.00 0.00 ATOM 52 CA LYS B 397 45.029 26.858 12.337 0.00 0.00 ATOM 53 CA TYR B 398 42.028 24.503 12.541 0.00 0.00 ATOM 54 CA LEU B 399 40.464 22.267 15.232 0.00 0.00 ATOM 55 CA THR B 400 37.758 19.511 14.875 0.00 0.00 ATOM 56 CA TRP B 401 35.457 18.407 17.801 0.00 0.00 ATOM 57 CA ALA B 402 32.954 15.412 18.104 0.00 0.00 ATOM 58 CA SER B 403 29.237 14.416 18.746 0.00 0.00 ATOM 59 CA ARG B 404 27.638 10.891 18.434 0.00 0.00 ATOM 60 CA GLN B 405 23.800 11.423 18.590 0.00 0.00 ATOM 61 CA GLU B 406 21.802 8.672 20.460 0.00 0.00 ATOM 62 CA PRO B 407 18.543 9.316 22.480 0.00 0.00 ATOM 63 CA SER B 408 15.859 6.724 23.598 0.00 0.00 ATOM 64 CA GLN B 409 14.414 6.459 20.006 0.00 0.00 ATOM 65 CA GLY B 410 15.625 4.735 16.763 0.00 0.00 ATOM 66 CA THR B 411 17.335 7.996 15.587 0.00 0.00 ATOM 67 CA THR B 412 21.181 7.498 15.847 0.00 0.00 ATOM 68 CA THR B 413 23.702 9.279 13.440 0.00 0.00 ATOM 69 CA PHE B 414 26.731 11.647 14.158 0.00 0.00 ATOM 70 CA ALA B 415 27.546 15.374 13.855 0.00 0.00 ATOM 71 CA VAL B 416 30.841 17.363 14.111 0.00 0.00 ATOM 72 CA THR B 417 31.840 21.022 13.716 0.00 0.00 ATOM 73 CA SER B 418 35.327 21.958 12.385 0.00 0.00 ATOM 74 CA ILE B 419 36.751 25.423 13.208 0.00 0.00 ATOM 75 CA LEU B 420 39.314 27.128 10.856 0.00 0.00 ATOM 76 CA ARG B 421 40.603 30.355 12.440 0.00 0.00 ATOM 77 CA VAL B 422 41.909 33.070 9.970 0.00 0.00 ATOM 78 CA ALA B 423 43.075 36.733 10.010 0.00 0.00 ATOM 79 CA ALA B 424 40.030 39.105 9.515 0.00 0.00 ATOM 80 CA GLU B 425 41.867 40.656 6.493 0.00 0.00 ATOM 81 CA ASP B 426 42.292 37.465 4.294 0.00 0.00 ATOM 82 CA TRP B 427 38.535 36.659 4.535 0.00 0.00 ATOM 83 CA LYS B 428 37.857 40.321 3.407 0.00 0.00 ATOM 84 CA LYS B 429 40.590 40.043 0.673 0.00 0.00 ATOM 85 CA GLY B 430 38.005 37.635 -0.901 0.00 0.00 ATOM 86 CA ASP B 431 39.808 34.341 -0.214 0.00 0.00 ATOM 87 CA THR B 432 38.103 30.971 -0.825 0.00 0.00 ATOM 88 CA PHE B 433 38.596 28.437 2.020 0.00 0.00 ATOM 89 CA SER B 434 37.316 24.844 1.533 0.00 0.00 ATOM 90 CA CYS B 435 36.362 22.165 4.064 0.00 0.00 ATOM 91 CA MET B 436 37.199 18.679 2.620 0.00 0.00 ATOM 92 CA VAL B 437 35.246 15.738 4.148 0.00 0.00 ATOM 93 CA GLY B 438 36.220 12.066 3.551 0.00 0.00 ATOM 94 CA HIS B 439 33.718 9.353 4.519 0.00 0.00 ATOM 95 CA GLU B 440 32.669 5.739 3.560 0.00 0.00 ATOM 96 CA ALA B 441 29.292 6.943 2.081 0.00 0.00 ATOM 97 CA LEU B 442 30.581 9.965 0.043 0.00 0.00 ATOM 98 CA PRO B 443 30.433 9.661 -3.841 0.00 0.00 ATOM 99 CA LEU B 444 34.224 9.336 -4.492 0.00 0.00 ATOM 100 CA ALA B 445 34.874 8.869 -0.700 0.00 0.00 ATOM 101 CA PHE B 446 35.499 12.649 -0.829 0.00 0.00 ATOM 102 CA THR B 447 33.457 15.874 -0.953 0.00 0.00 ATOM 103 CA GLN B 448 34.585 19.507 -0.558 0.00 0.00 ATOM 104 CA LYS B 449 32.313 22.515 0.276 0.00 0.00 ATOM 105 CA THR B 450 33.700 26.083 -0.123 0.00 0.00 ATOM 106 CA ILE B 451 33.486 29.430 1.831 0.00 0.00 ATOM 107 CA ASP B 452 34.349 32.981 0.621 0.00 0.00 ATOM 108 CA ARG B 453 33.383 36.652 1.405 0.00 0.00 TER