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 115 THR PRO SER PRO SER THR PRO PRO THR PRO SER PRO SER SEQRES 2 A 115 CYS CYS HIS PRO ARG LEU SER LEU HIS ARG PRO ALA LEU SEQRES 3 A 115 GLU ASP LEU LEU LEU GLY SER GLU ALA ASN LEU THR CYS SEQRES 4 A 115 THR LEU THR GLY LEU ARG ASP ALA SER GLY VAL THR PHE SEQRES 5 A 115 THR TRP THR PRO SER SER GLY LYS SER ALA VAL GLN GLY SEQRES 6 A 115 PRO PRO GLU ARG ASP LEU CYS GLY CYS TYR SER VAL SER SEQRES 7 A 115 SER VAL LEU PRO GLY CYS ALA GLU PRO TRP ASN HIS GLY SEQRES 8 A 115 LYS THR PHE THR CYS THR ALA ALA TYR PRO GLU SER LYS SEQRES 9 A 115 THR PRO LEU THR ALA THR LEU SER LYS SER GLY ATOM 1 CA THR A 231 44.411 -52.471 54.498 1.00 0.00 ATOM 2 CA PRO A 232 43.469 -49.962 51.600 1.00 0.00 ATOM 3 CA SER A 233 44.473 -46.250 52.271 1.00 0.00 ATOM 4 CA PRO A 234 41.277 -43.993 52.445 1.00 0.00 ATOM 5 CA SER A 235 43.269 -40.655 52.092 1.00 0.00 ATOM 6 CA THR A 236 42.141 -37.208 50.654 1.00 0.00 ATOM 7 CA PRO A 237 44.719 -34.328 50.672 1.00 0.00 ATOM 8 CA PRO A 238 42.975 -30.688 50.617 1.00 0.00 ATOM 9 CA THR A 239 45.690 -27.938 49.352 1.00 0.00 ATOM 10 CA PRO A 240 44.528 -24.135 48.734 1.00 0.00 ATOM 11 CA SER A 241 46.521 -21.275 46.646 1.00 0.00 ATOM 12 CA PRO A 242 48.219 -17.724 46.680 1.00 0.00 ATOM 13 CA SER A 243 48.073 -14.512 44.570 1.00 0.00 ATOM 14 CA CYS A 244 50.047 -11.291 44.002 1.00 0.00 ATOM 15 CA CYS A 245 51.123 -8.414 46.546 1.00 0.00 ATOM 16 CA HIS A 246 52.333 -5.144 44.994 1.00 0.00 ATOM 17 CA PRO A 247 52.274 -1.576 46.894 0.00 0.00 ATOM 18 CA ARG A 248 50.755 1.060 44.484 0.00 0.00 ATOM 19 CA LEU A 249 48.830 4.230 45.668 0.00 0.00 ATOM 20 CA SER A 250 46.224 5.595 43.138 0.00 0.00 ATOM 21 CA LEU A 251 43.826 8.619 43.350 0.00 0.00 ATOM 22 CA HIS A 252 40.683 8.434 41.110 0.00 0.00 ATOM 23 CA ARG A 253 39.042 11.938 40.698 0.00 0.00 ATOM 24 CA PRO A 254 35.238 12.765 40.897 0.00 0.00 ATOM 25 CA ALA A 255 33.190 12.623 37.587 0.00 0.00 ATOM 26 CA LEU A 256 32.205 15.957 35.832 0.00 0.00 ATOM 27 CA GLU A 257 28.468 15.151 35.141 0.00 0.00 ATOM 28 CA ASP A 258 27.696 13.960 38.769 0.00 0.00 ATOM 29 CA LEU A 259 29.456 16.942 40.522 0.00 0.00 ATOM 30 CA LEU A 260 27.650 19.483 38.197 0.00 0.00 ATOM 31 CA LEU A 261 24.125 17.847 38.263 0.00 0.00 ATOM 32 CA GLY A 262 23.206 17.766 42.026 0.00 0.00 ATOM 33 CA SER A 263 26.631 18.219 43.842 0.00 0.00 ATOM 34 CA GLU A 264 27.632 14.472 43.821 0.00 0.00 ATOM 35 CA ALA A 265 31.487 14.156 43.961 0.00 0.00 ATOM 36 CA ASN A 266 33.709 11.520 45.679 0.00 0.00 ATOM 37 CA LEU A 267 37.538 11.601 45.532 0.00 0.00 ATOM 38 CA THR A 268 38.607 7.962 45.796 0.00 0.00 ATOM 39 CA CYS A 269 41.875 6.668 47.349 0.00 0.00 ATOM 40 CA THR A 270 43.060 3.173 46.355 0.00 0.00 ATOM 41 CA LEU A 271 46.102 1.359 47.910 0.00 0.00 ATOM 42 CA THR A 272 47.074 -1.556 45.611 0.00 0.00 ATOM 43 CA GLY A 273 50.161 -3.732 46.476 0.00 0.00 ATOM 44 CA LEU A 274 50.086 -4.055 50.344 0.00 0.00 ATOM 45 CA ARG A 275 51.625 -7.607 50.925 0.00 0.00 ATOM 46 CA ASP A 276 50.486 -10.344 53.467 0.00 0.00 ATOM 47 CA ALA A 277 49.537 -9.727 57.221 0.00 0.00 ATOM 48 CA SER A 278 48.814 -5.995 56.861 0.00 0.00 ATOM 49 CA GLY A 279 46.596 -2.850 57.364 0.00 0.00 ATOM 50 CA VAL A 280 46.460 0.730 55.904 0.00 0.00 ATOM 51 CA THR A 281 45.843 4.004 57.889 0.00 0.00 ATOM 52 CA PHE A 282 44.298 6.895 55.913 0.00 0.00 ATOM 53 CA THR A 283 44.642 10.692 56.586 0.00 0.00 ATOM 54 CA TRP A 284 42.355 12.884 54.334 0.00 0.00 ATOM 55 CA THR A 285 42.284 16.761 54.321 0.00 0.00 ATOM 56 CA PRO A 286 38.696 18.132 54.948 0.00 0.00 ATOM 57 CA SER A 287 36.659 19.842 52.123 0.00 0.00 ATOM 58 CA SER A 288 36.155 23.682 52.362 0.00 0.00 ATOM 59 CA GLY A 289 32.983 23.767 54.604 0.00 0.00 ATOM 60 CA LYS A 290 34.805 21.890 57.491 0.00 0.00 ATOM 61 CA SER A 291 33.913 18.346 56.224 0.00 0.00 ATOM 62 CA ALA A 292 35.983 15.077 56.496 0.00 0.00 ATOM 63 CA VAL A 293 34.006 11.752 56.110 0.00 0.00 ATOM 64 CA GLN A 294 35.608 8.332 55.141 0.00 0.00 ATOM 65 CA GLY A 295 34.797 4.540 54.703 0.00 0.00 ATOM 66 CA PRO A 296 37.827 2.150 54.268 0.00 0.00 ATOM 67 CA PRO A 297 37.315 -1.655 53.545 0.00 0.00 ATOM 68 CA GLU A 298 40.230 -4.134 52.863 0.00 0.00 ATOM 69 CA ARG A 299 39.716 -6.103 49.594 0.00 0.00 ATOM 70 CA ASP A 300 42.129 -8.916 48.452 0.00 0.00 ATOM 71 CA LEU A 301 42.619 -8.256 44.640 0.00 0.00 ATOM 72 CA CYS A 302 44.792 -10.655 42.461 0.00 0.00 ATOM 73 CA GLY A 303 46.156 -12.256 45.682 0.00 0.00 ATOM 74 CA CYS A 304 46.910 -9.180 47.940 0.00 0.00 ATOM 75 CA TYR A 305 45.091 -6.490 50.099 0.00 0.00 ATOM 76 CA SER A 306 43.742 -3.099 48.786 0.00 0.00 ATOM 77 CA VAL A 307 42.529 -0.386 51.283 0.00 0.00 ATOM 78 CA SER A 308 40.119 1.662 49.174 0.00 0.00 ATOM 79 CA SER A 309 38.788 4.656 51.116 0.00 0.00 ATOM 80 CA VAL A 310 36.379 7.335 49.749 0.00 0.00 ATOM 81 CA LEU A 311 35.857 11.031 50.750 0.00 0.00 ATOM 82 CA PRO A 312 32.403 12.481 49.687 0.00 0.00 ATOM 83 CA GLY A 313 32.639 16.135 48.467 0.00 0.00 ATOM 84 CA CYS A 314 30.483 19.144 47.470 0.00 0.00 ATOM 85 CA ALA A 315 30.570 21.078 44.108 0.00 0.00 ATOM 86 CA GLU A 316 31.891 24.433 45.603 0.00 0.00 ATOM 87 CA PRO A 317 35.379 23.167 46.862 0.00 0.00 ATOM 88 CA TRP A 318 35.982 21.424 43.440 0.00 0.00 ATOM 89 CA ASN A 319 34.721 24.465 41.341 0.00 0.00 ATOM 90 CA HIS A 320 36.471 27.247 43.452 0.00 0.00 ATOM 91 CA GLY A 321 39.914 25.507 43.945 0.00 0.00 ATOM 92 CA LYS A 322 40.541 23.037 46.859 0.00 0.00 ATOM 93 CA THR A 323 43.545 20.608 47.257 0.00 0.00 ATOM 94 CA PHE A 324 42.478 17.073 48.386 0.00 0.00 ATOM 95 CA THR A 325 45.298 15.141 50.071 0.00 0.00 ATOM 96 CA CYS A 326 45.102 11.380 50.773 0.00 0.00 ATOM 97 CA THR A 327 48.055 10.564 53.057 0.00 0.00 ATOM 98 CA ALA A 328 48.406 6.840 53.788 0.00 0.00 ATOM 99 CA ALA A 329 50.700 5.341 56.533 0.00 0.00 ATOM 100 CA TYR A 330 51.942 1.656 56.769 0.00 0.00 ATOM 101 CA PRO A 331 55.079 0.263 58.670 0.00 0.00 ATOM 102 CA GLU A 332 56.672 -1.514 55.589 0.00 0.00 ATOM 103 CA SER A 333 56.242 1.813 53.608 0.00 0.00 ATOM 104 CA LYS A 334 59.095 3.792 55.369 0.00 0.00 ATOM 105 CA THR A 335 57.855 7.140 53.878 0.00 0.00 ATOM 106 CA PRO A 336 54.009 7.515 54.392 0.00 0.00 ATOM 107 CA LEU A 337 52.568 8.234 50.875 0.00 0.00 ATOM 108 CA THR A 338 50.864 11.575 50.270 0.00 0.00 ATOM 109 CA ALA A 339 48.827 12.099 47.018 0.00 0.00 ATOM 110 CA THR A 340 47.114 15.509 46.453 0.00 0.00 ATOM 111 CA LEU A 341 44.445 16.389 43.857 0.00 0.00 ATOM 112 CA SER A 342 42.552 19.607 42.735 0.00 0.00 ATOM 113 CA LYS A 343 41.225 21.617 39.674 0.00 0.00 ATOM 114 CA SER A 344 43.470 22.529 36.634 0.00 0.00 ATOM 115 CA GLY A 345 45.418 25.666 35.447 0.00 0.00 TER