ATOM 179 N PHE B 1 -21.779 1.268 3.594 1.00 16.68 N ATOM 180 CA PHE B 1 -20.289 1.299 3.938 1.00 12.98 C ATOM 181 C PHE B 1 -20.117 1.092 5.388 1.00 14.07 C ATOM 182 O PHE B 1 -21.067 1.216 6.147 1.00 21.25 O ATOM 183 CB PHE B 1 -19.618 2.557 3.477 1.00 13.55 C ATOM 184 CG PHE B 1 -19.778 2.811 1.999 1.00 11.20 C ATOM 185 CD1 PHE B 1 -20.293 3.965 1.538 1.00 16.36 C ATOM 186 CD2 PHE B 1 -19.305 1.936 1.059 1.00 14.08 C ATOM 187 CE1 PHE B 1 -20.449 4.232 0.174 1.00 16.68 C ATOM 188 CE2 PHE B 1 -19.426 2.190 -0.325 1.00 14.48 C ATOM 189 CZ PHE B 1 -20.056 3.330 -0.745 1.00 16.14 C ATOM 190 N VAL B 2 -18.923 0.719 5.789 1.00 11.98 N ATOM 191 CA VAL B 2 -18.613 0.465 7.219 1.00 10.85 C ATOM 192 C VAL B 2 -17.754 1.602 7.757 1.00 9.09 C ATOM 193 O VAL B 2 -17.079 2.313 6.993 1.00 9.20 O ATOM 194 CB VAL B 2 -17.875 -0.912 7.425 1.00 12.92 C ATOM 195 CG1 VAL B 2 -18.747 -2.096 7.072 1.00 16.00 C ATOM 196 CG2 VAL B 2 -16.527 -0.972 6.649 1.00 13.39 C ATOM 197 N ASN B 3 -17.718 1.753 9.083 1.00 9.61 N ATOM 198 CA ASN B 3 -16.821 2.724 9.677 1.00 9.74 C ATOM 199 C ASN B 3 -15.404 2.206 9.617 1.00 9.76 C ATOM 200 O ASN B 3 -15.155 0.986 9.399 1.00 11.05 O ATOM 201 CB ASN B 3 -17.226 3.033 11.079 1.00 12.80 C ATOM 202 CG ASN B 3 -18.542 3.801 11.121 1.00 12.32 C ATOM 203 OD1 ASN B 3 -18.707 4.781 10.363 1.00 19.81 O ATOM 204 ND2 ASN B 3 -19.414 3.405 12.015 1.00 18.23 N ATOM 205 N AGLN B 4 -14.477 3.160 9.813 0.60 9.28 N ATOM 206 N BGLN B 4 -14.418 3.087 9.659 0.40 9.99 N ATOM 207 CA AGLN B 4 -13.040 3.022 9.504 0.60 8.44 C ATOM 208 CA BGLN B 4 -13.060 2.555 9.575 0.40 10.23 C ATOM 209 C AGLN B 4 -12.181 3.343 10.688 0.60 7.71 C ATOM 210 C BGLN B 4 -12.187 3.238 10.612 0.40 8.85 C ATOM 211 O AGLN B 4 -12.438 4.340 11.385 0.60 10.66 O ATOM 212 O BGLN B 4 -12.455 4.308 11.139 0.40 10.54 O ATOM 213 CB AGLN B 4 -12.721 4.042 8.417 0.60 7.13 C ATOM 214 CB BGLN B 4 -12.460 2.717 8.179 0.40 11.09 C ATOM 215 CG AGLN B 4 -13.652 3.883 7.188 0.60 7.58 C ATOM 216 CG BGLN B 4 -11.118 2.332 8.234 0.40 16.94 C ATOM 217 CD AGLN B 4 -13.499 2.557 6.450 0.60 11.04 C ATOM 218 CD BGLN B 4 -10.939 0.793 8.294 0.40 16.06 C ATOM 219 OE1AGLN B 4 -12.438 1.986 6.435 0.60 18.78 O ATOM 220 OE1BGLN B 4 -10.847 0.222 7.209 0.40 21.61 O ATOM 221 NE2AGLN B 4 -14.531 2.088 5.861 0.60 10.04 N ATOM 222 NE2BGLN B 4 -10.974 0.115 9.537 0.40 12.74 N ATOM 223 N HIS B 5 -11.095 2.562 10.885 1.00 8.47 N ATOM 224 CA HIS B 5 -10.023 2.999 11.797 1.00 7.98 C ATOM 225 C HIS B 5 -8.783 3.171 10.905 1.00 8.00 C ATOM 226 O HIS B 5 -8.315 2.161 10.386 1.00 8.78 O ATOM 227 CB HIS B 5 -9.801 1.882 12.818 1.00 9.14 C ATOM 228 CG HIS B 5 -8.751 2.224 13.802 1.00 10.55 C ATOM 229 ND1 HIS B 5 -8.106 1.263 14.568 1.00 12.69 N ATOM 230 CD2 HIS B 5 -8.237 3.429 14.185 1.00 10.50 C ATOM 231 CE1 HIS B 5 -7.211 1.874 15.344 1.00 15.03 C ATOM 232 NE2 HIS B 5 -7.289 3.185 15.150 1.00 13.40 N ATOM 233 N LEU B 6 -8.360 4.436 10.671 1.00 6.57 N ATOM 234 CA LEU B 6 -7.343 4.693 9.656 1.00 7.02 C ATOM 235 C LEU B 6 -6.303 5.616 10.238 1.00 6.33 C ATOM 236 O LEU B 6 -6.619 6.746 10.619 1.00 9.35 O ATOM 237 CB LEU B 6 -7.989 5.372 8.385 1.00 8.46 C ATOM 238 CG LEU B 6 -9.048 4.522 7.720 1.00 7.53 C ATOM 239 CD1 LEU B 6 -9.967 5.470 6.858 1.00 10.20 C ATOM 240 CD2 LEU B 6 -8.390 3.378 6.927 1.00 9.54 C ATOM 241 N CYS B 7 -5.063 5.151 10.244 1.00 8.43 N ATOM 242 CA CYS B 7 -3.921 5.952 10.686 1.00 10.04 C ATOM 243 C CYS B 7 -2.880 6.093 9.585 1.00 10.30 C ATOM 244 O CYS B 7 -2.755 5.268 8.674 1.00 10.27 O ATOM 245 CB CYS B 7 -3.195 5.272 11.845 1.00 10.61 C ATOM 246 SG CYS B 7 -4.241 5.087 13.341 1.00 12.93 S ATOM 247 N GLY B 8 -2.104 7.162 9.649 1.00 12.15 N ATOM 248 CA GLY B 8 -0.984 7.333 8.728 1.00 13.03 C ATOM 249 C GLY B 8 -1.373 7.289 7.259 1.00 10.74 C ATOM 250 O GLY B 8 -2.411 7.858 6.799 1.00 12.81 O ATOM 251 N SER B 9 -0.602 6.541 6.500 1.00 9.84 N ATOM 252 CA SER B 9 -0.813 6.479 5.089 1.00 9.19 C ATOM 253 C SER B 9 -2.117 5.756 4.718 1.00 7.84 C ATOM 254 O SER B 9 -2.599 5.925 3.607 1.00 8.42 O ATOM 255 CB SER B 9 0.387 5.891 4.372 1.00 10.51 C ATOM 256 OG SER B 9 0.616 4.598 4.829 1.00 12.23 O ATOM 257 N HIS B 10 -2.663 4.938 5.625 1.00 7.69 N ATOM 258 CA HIS B 10 -3.897 4.287 5.327 1.00 6.80 C ATOM 259 C HIS B 10 -5.037 5.292 5.196 1.00 6.77 C ATOM 260 O HIS B 10 -5.988 5.085 4.386 1.00 7.53 O ATOM 261 CB HIS B 10 -4.249 3.289 6.447 1.00 7.67 C ATOM 262 CG HIS B 10 -3.222 2.240 6.577 1.00 7.36 C ATOM 263 ND1 HIS B 10 -2.965 1.289 5.607 1.00 9.92 N ATOM 264 CD2 HIS B 10 -2.276 2.028 7.545 1.00 7.09 C ATOM 265 CE1 HIS B 10 -1.948 0.497 6.008 1.00 10.24 C ATOM 266 NE2 HIS B 10 -1.539 0.892 7.213 1.00 6.01 N ATOM 267 N LEU B 11 -4.974 6.404 5.931 1.00 7.22 N ATOM 268 CA LEU B 11 -6.029 7.446 5.747 1.00 7.71 C ATOM 269 C LEU B 11 -5.900 8.080 4.389 1.00 6.71 C ATOM 270 O LEU B 11 -6.916 8.350 3.740 1.00 6.90 O ATOM 271 CB LEU B 11 -5.895 8.470 6.863 1.00 8.53 C ATOM 272 CG LEU B 11 -6.852 9.618 6.758 1.00 10.95 C ATOM 273 CD1 LEU B 11 -8.337 9.130 6.670 1.00 13.71 C ATOM 274 CD2 LEU B 11 -6.710 10.543 7.857 1.00 16.26 C ATOM 275 N AVAL B 12 -4.665 8.327 3.912 0.50 7.10 N ATOM 276 N BVAL B 12 -4.659 8.321 3.913 0.50 6.97 N ATOM 277 CA AVAL B 12 -4.616 8.971 2.627 0.50 6.80 C ATOM 278 CA BVAL B 12 -4.447 8.903 2.606 0.50 6.36 C ATOM 279 C AVAL B 12 -5.047 8.033 1.503 0.50 6.83 C ATOM 280 C BVAL B 12 -4.984 8.024 1.481 0.50 6.74 C ATOM 281 O AVAL B 12 -5.651 8.512 0.547 0.50 7.09 O ATOM 282 O BVAL B 12 -5.574 8.511 0.510 0.50 7.23 O ATOM 283 CB AVAL B 12 -3.258 9.631 2.314 0.50 8.70 C ATOM 284 CB BVAL B 12 -2.906 9.121 2.411 0.50 7.23 C ATOM 285 CG1AVAL B 12 -2.932 10.746 3.301 0.50 9.84 C ATOM 286 CG1BVAL B 12 -2.616 9.539 0.993 0.50 6.59 C ATOM 287 CG2AVAL B 12 -2.198 8.647 2.385 0.50 11.88 C ATOM 288 CG2BVAL B 12 -2.421 10.203 3.411 0.50 8.22 C ATOM 289 N GLU B 13 -4.791 6.707 1.617 1.00 6.84 N ATOM 290 CA GLU B 13 -5.330 5.795 0.665 1.00 6.62 C ATOM 291 C GLU B 13 -6.864 5.838 0.637 1.00 7.19 C ATOM 292 O GLU B 13 -7.503 5.767 -0.432 1.00 7.51 O ATOM 293 CB GLU B 13 -4.881 4.356 0.977 1.00 8.88 C ATOM 294 CG GLU B 13 -3.445 4.011 0.816 1.00 14.60 C ATOM 295 CD GLU B 13 -3.130 3.794 -0.622 1.00 19.09 C ATOM 296 OE1 GLU B 13 -1.888 3.785 -0.891 1.00 19.25 O ATOM 297 OE2 GLU B 13 -4.076 3.707 -1.489 1.00 21.13 O ATOM 298 N ALA B 14 -7.492 5.928 1.834 1.00 5.92 N ATOM 299 CA ALA B 14 -8.930 6.024 1.887 1.00 6.61 C ATOM 300 C ALA B 14 -9.453 7.319 1.249 1.00 6.83 C ATOM 301 O ALA B 14 -10.456 7.287 0.487 1.00 7.46 O ATOM 302 CB ALA B 14 -9.448 5.931 3.331 1.00 7.12 C ATOM 303 N LEU B 15 -8.796 8.443 1.508 1.00 5.75 N ATOM 304 CA LEU B 15 -9.201 9.669 0.825 1.00 6.95 C ATOM 305 C LEU B 15 -9.067 9.534 -0.685 1.00 6.26 C ATOM 306 O LEU B 15 -9.939 10.060 -1.437 1.00 7.39 O ATOM 307 CB LEU B 15 -8.303 10.864 1.353 1.00 7.29 C ATOM 308 CG LEU B 15 -8.719 11.354 2.724 1.00 7.53 C ATOM 309 CD1 LEU B 15 -7.542 12.218 3.282 1.00 11.12 C ATOM 310 CD2 LEU B 15 -9.984 12.130 2.674 1.00 10.16 C ATOM 311 N TYR B 16 -7.983 8.909 -1.137 1.00 7.07 N ATOM 312 CA TYR B 16 -7.846 8.768 -2.564 1.00 7.01 C ATOM 313 C TYR B 16 -8.991 7.991 -3.173 1.00 7.28 C ATOM 314 O TYR B 16 -9.542 8.356 -4.216 1.00 8.61 O ATOM 315 CB TYR B 16 -6.491 8.074 -2.818 1.00 7.93 C ATOM 316 CG TYR B 16 -6.293 7.755 -4.274 1.00 8.51 C ATOM 317 CD1 TYR B 16 -6.596 6.495 -4.784 1.00 10.56 C ATOM 318 CD2 TYR B 16 -5.859 8.740 -5.178 1.00 10.90 C ATOM 319 CE1 TYR B 16 -6.467 6.211 -6.138 1.00 12.94 C ATOM 320 CE2 TYR B 16 -5.766 8.442 -6.575 1.00 14.06 C ATOM 321 CZ TYR B 16 -6.070 7.197 -7.015 1.00 13.67 C ATOM 322 OH TYR B 16 -5.923 6.888 -8.345 1.00 21.38 O ATOM 323 N ALEU B 17 -9.400 6.912 -2.519 0.60 6.68 N ATOM 324 N BLEU B 17 -9.348 6.896 -2.521 0.40 7.46 N ATOM 325 CA ALEU B 17 -10.506 6.066 -3.060 0.60 7.54 C ATOM 326 CA BLEU B 17 -10.455 6.070 -3.017 0.40 8.56 C ATOM 327 C ALEU B 17 -11.834 6.803 -2.975 0.60 7.81 C ATOM 328 C BLEU B 17 -11.779 6.814 -2.983 0.40 8.25 C ATOM 329 O ALEU B 17 -12.670 6.714 -3.898 0.60 9.94 O ATOM 330 O BLEU B 17 -12.555 6.727 -3.945 0.40 9.49 O ATOM 331 CB ALEU B 17 -10.525 4.735 -2.248 0.60 7.94 C ATOM 332 CB BLEU B 17 -10.576 4.812 -2.146 0.40 9.41 C ATOM 333 CG ALEU B 17 -9.325 3.804 -2.549 0.60 7.59 C ATOM 334 CG BLEU B 17 -11.768 3.969 -2.575 0.40 9.49 C ATOM 335 CD1ALEU B 17 -9.386 2.670 -1.568 0.60 9.34 C ATOM 336 CD1BLEU B 17 -13.061 4.697 -2.698 0.40 17.29 C ATOM 337 CD2ALEU B 17 -9.507 3.318 -3.971 0.60 11.70 C ATOM 338 CD2BLEU B 17 -11.405 3.307 -3.839 0.40 14.07 C ATOM 339 N VAL B 18 -12.092 7.458 -1.871 1.00 7.62 N ATOM 340 CA VAL B 18 -13.367 8.212 -1.762 1.00 7.47 C ATOM 341 C VAL B 18 -13.477 9.288 -2.762 1.00 7.70 C ATOM 342 O VAL B 18 -14.531 9.530 -3.379 1.00 10.68 O ATOM 343 CB VAL B 18 -13.545 8.728 -0.304 1.00 7.45 C ATOM 344 CG1 VAL B 18 -14.706 9.743 -0.221 1.00 9.96 C ATOM 345 CG2 VAL B 18 -13.738 7.546 0.646 1.00 8.90 C ATOM 346 N CYS B 19 -12.405 10.052 -2.921 1.00 7.37 N ATOM 347 CA CYS B 19 -12.513 11.304 -3.689 1.00 8.80 C ATOM 348 C CYS B 19 -12.204 11.116 -5.183 1.00 9.54 C ATOM 349 O CYS B 19 -12.773 11.878 -6.011 1.00 11.11 O ATOM 350 CB CYS B 19 -11.509 12.365 -3.150 1.00 8.22 C ATOM 351 SG CYS B 19 -11.960 12.763 -1.437 1.00 8.12 S ATOM 352 N GLY B 20 -11.373 10.132 -5.536 1.00 11.46 N ATOM 353 CA GLY B 20 -11.065 9.845 -6.977 1.00 12.93 C ATOM 354 C GLY B 20 -10.586 11.150 -7.644 1.00 12.61 C ATOM 355 O GLY B 20 -9.779 11.963 -7.079 1.00 13.35 O ATOM 356 N GLU B 21 -11.154 11.419 -8.835 1.00 14.49 N ATOM 357 CA GLU B 21 -10.644 12.500 -9.613 1.00 14.06 C ATOM 358 C GLU B 21 -11.009 13.871 -9.039 1.00 11.54 C ATOM 359 O GLU B 21 -10.477 14.924 -9.500 1.00 12.69 O ATOM 360 CB GLU B 21 -11.111 12.365 -11.032 1.00 15.17 C ATOM 361 CG GLU B 21 -12.596 12.609 -11.131 1.00 19.86 C ATOM 362 CD GLU B 21 -12.984 12.763 -12.590 1.00 27.23 C ATOM 363 OE1 GLU B 21 -14.132 13.090 -12.821 1.00 30.01 O ATOM 364 OE2 GLU B 21 -12.102 12.561 -13.486 1.00 32.12 O ATOM 365 N ARG B 22 -11.872 13.919 -8.021 1.00 11.20 N ATOM 366 CA ARG B 22 -12.141 15.191 -7.391 1.00 11.49 C ATOM 367 C ARG B 22 -10.919 15.680 -6.652 1.00 11.40 C ATOM 368 O ARG B 22 -10.830 16.879 -6.401 1.00 13.67 O ATOM 369 CB ARG B 22 -13.236 15.137 -6.320 1.00 13.28 C ATOM 370 CG ARG B 22 -14.635 14.828 -6.883 1.00 16.96 C ATOM 371 CD ARG B 22 -15.621 14.789 -5.675 1.00 18.28 C ATOM 372 NE ARG B 22 -15.539 13.443 -5.114 1.00 23.10 N ATOM 373 CZ ARG B 22 -16.446 13.007 -4.221 1.00 19.79 C ATOM 374 NH1 ARG B 22 -17.421 13.882 -3.817 1.00 23.96 N ATOM 375 NH2 ARG B 22 -16.370 11.764 -3.756 1.00 19.23 N ATOM 376 N GLY B 23 -9.991 14.789 -6.282 1.00 9.85 N ATOM 377 CA GLY B 23 -8.869 15.207 -5.429 1.00 11.47 C ATOM 378 C GLY B 23 -9.262 15.460 -3.993 1.00 7.29 C ATOM 379 O GLY B 23 -10.481 15.352 -3.641 1.00 8.16 O ATOM 380 N PHE B 24 -8.308 15.772 -3.161 1.00 6.90 N ATOM 381 CA PHE B 24 -8.604 15.996 -1.757 1.00 6.76 C ATOM 382 C PHE B 24 -7.535 16.796 -1.090 1.00 6.31 C ATOM 383 O PHE B 24 -6.399 16.979 -1.623 1.00 7.12 O ATOM 384 CB PHE B 24 -8.773 14.652 -1.028 1.00 7.24 C ATOM 385 CG PHE B 24 -7.535 13.769 -1.024 1.00 5.87 C ATOM 386 CD1 PHE B 24 -7.349 12.837 -2.024 1.00 6.72 C ATOM 387 CD2 PHE B 24 -6.557 13.872 -0.026 1.00 6.55 C ATOM 388 CE1 PHE B 24 -6.232 12.014 -2.056 1.00 8.17 C ATOM 389 CE2 PHE B 24 -5.461 13.061 -0.034 1.00 7.23 C ATOM 390 CZ PHE B 24 -5.305 12.097 -1.055 1.00 8.31 C ATOM 391 N PHE B 25 -7.836 17.233 0.141 1.00 7.82 N ATOM 392 CA PHE B 25 -6.832 17.832 1.004 1.00 7.87 C ATOM 393 C PHE B 25 -6.580 16.984 2.222 1.00 8.21 C ATOM 394 O PHE B 25 -7.563 16.494 2.831 1.00 10.14 O ATOM 395 CB PHE B 25 -7.376 19.233 1.516 1.00 12.91 C ATOM 396 CG PHE B 25 -7.764 20.095 0.413 1.00 16.38 C ATOM 397 CD1 PHE B 25 -9.102 20.017 -0.165 1.00 18.23 C ATOM 398 CD2 PHE B 25 -6.798 20.940 -0.141 1.00 17.56 C ATOM 399 CE1 PHE B 25 -9.414 20.774 -1.224 1.00 20.41 C ATOM 400 CE2 PHE B 25 -7.085 21.765 -1.310 1.00 20.42 C ATOM 401 CZ PHE B 25 -8.400 21.690 -1.790 1.00 22.04 C ATOM 402 N TYR B 26 -5.311 16.767 2.538 1.00 7.86 N ATOM 403 CA TYR B 26 -4.875 16.005 3.716 1.00 7.01 C ATOM 404 C TYR B 26 -4.362 17.029 4.704 1.00 9.07 C ATOM 405 O TYR B 26 -3.366 17.698 4.442 1.00 8.67 O ATOM 406 CB TYR B 26 -3.794 15.011 3.341 1.00 7.63 C ATOM 407 CG TYR B 26 -3.196 14.278 4.526 1.00 8.93 C ATOM 408 CD1 TYR B 26 -4.027 13.380 5.266 1.00 11.36 C ATOM 409 CD2 TYR B 26 -1.895 14.508 4.929 1.00 9.48 C ATOM 410 CE1 TYR B 26 -3.488 12.697 6.338 1.00 11.22 C ATOM 411 CE2 TYR B 26 -1.369 13.842 6.034 1.00 10.16 C ATOM 412 CZ TYR B 26 -2.166 12.942 6.724 1.00 11.73 C ATOM 413 OH TYR B 26 -1.625 12.292 7.854 1.00 14.97 O ATOM 414 N THR B 27 -5.081 17.237 5.830 1.00 9.25 N ATOM 415 CA THR B 27 -4.751 18.351 6.676 1.00 12.17 C ATOM 416 C THR B 27 -4.671 17.907 8.158 1.00 11.21 C ATOM 417 O THR B 27 -5.654 18.059 8.929 1.00 12.49 O ATOM 418 CB THR B 27 -5.851 19.488 6.514 1.00 15.09 C ATOM 419 OG1 THR B 27 -7.196 18.986 6.843 1.00 20.31 O ATOM 420 CG2 THR B 27 -5.868 19.898 5.076 1.00 15.62 C ATOM 421 N PRO B 28 -3.555 17.281 8.546 1.00 11.90 N ATOM 422 CA PRO B 28 -3.327 16.846 9.969 1.00 13.71 C ATOM 423 C PRO B 28 -3.251 18.055 10.857 1.00 13.67 C ATOM 424 O PRO B 28 -2.842 19.141 10.427 1.00 13.86 O ATOM 425 CB PRO B 28 -1.961 16.066 9.921 1.00 15.58 C ATOM 426 CG PRO B 28 -1.451 16.414 8.630 1.00 16.68 C ATOM 427 CD PRO B 28 -2.427 16.958 7.669 1.00 12.73 C ATOM 428 N LYS B 29 -3.536 17.857 12.132 1.00 14.58 N ATOM 429 CA LYS B 29 -3.220 18.868 13.196 1.00 17.70 C ATOM 430 C LYS B 29 -1.762 19.022 13.207 1.00 18.04 C ATOM 431 O LYS B 29 -1.002 18.010 13.209 1.00 19.94 O ATOM 432 CB LYS B 29 -3.704 18.311 14.541 1.00 18.73 C ATOM 433 CG LYS B 29 -5.035 18.911 14.857 1.00 22.94 C ATOM 434 CD LYS B 29 -5.452 18.398 16.205 1.00 24.59 C ATOM 435 CE LYS B 29 -4.525 18.958 17.209 1.00 24.05 C ATOM 436 NZ LYS B 29 -4.900 19.103 18.567 1.00 26.14 N ATOM 437 N THR B 30 -1.307 20.239 13.413 1.00 22.22 N ATOM 438 CA THR B 30 -0.008 20.427 13.968 1.00 26.68 C ATOM 439 C THR B 30 0.189 20.724 15.417 1.00 28.61 C ATOM 440 O THR B 30 -0.760 21.111 16.140 1.00 29.98 O ATOM 441 CB THR B 30 0.746 21.526 13.030 1.00 27.58 C ATOM 442 OG1 THR B 30 0.053 22.782 13.138 1.00 28.10 O ATOM 443 CG2 THR B 30 0.722 21.118 11.544 1.00 31.96 C ATOM 444 OXT THR B 30 1.338 20.563 15.829 1.00 30.50 O