ID code: '5G4V' CHIRALITY (03 Nov 1998) Checks the chirality and the naming of substituents of chiral and prochiral centers in nucleic acid structures. The molecular structure is read from a PDB file. Only the first model is evaluated. ---------------------------------------------------------- Center Reference for correct naming ---------------------------------------------------------- C1' alpha/beta nomenclature of anomeric sugars, base in beta position in natural nucleosids. C2' IUPAC. 1983. Eur J Biochem, 131: 9-15. C3' IUPAC. 1983. Eur J Biochem, 131: 9-15. C4' IUPAC. 1983. Eur J Biochem, 131: 9-15. C5' IUPAC. 1983. Eur J Biochem, 131: 9-15. P Brookhaven PDB entry '1BNA', O1P -> major groove, O2P -> minor groove. ---------------------------------------------------------- Author: Peter Slickers (slickers@imb-jena.de) Biocomputing, IMB Jena, Germany --------------------------------------------------------------------------------- Seq No Atom Residue H1' base O4' H1' base C2' --------------------------------------------------------------------------------- 9 C1' G A 1 beta 4 10 7 32 C1' G A 2 beta 27 33 30 55 C1' C A 3 beta 50 56 53 75 C1' G A 4 beta 70 76 73 98 C1' A A 5 beta 93 99 96 120 C1' A A 6 beta 115 121 118 142 C1' G A 7 beta 137 143 140 165 C1' A A 8 beta 160 166 163 187 C1' G A 9 beta 182 188 185 210 C1' C A 10 beta 205 211 208 230 C1' C A 11 beta 225 231 228 250 C1' G A 12 beta 245 251 248 273 C1' G A 13 beta 268 274 271 296 C1' C A 14 beta 291 297 294 316 C1' G A 15 beta 311 317 314 339 C1' A A 16 beta 334 340 337 361 C1' G A 17 beta 356 362 359 384 C1' C A 18 beta 379 385 382 404 C1' C A 19 beta 399 405 402 422 C1' G B 1 beta 417 423 420 445 C1' G B 2 beta 440 446 443 468 C1' C B 3 beta 463 469 466 488 C1' G B 4 beta 483 489 486 511 C1' A B 5 beta 506 512 509 533 C1' A B 6 beta 528 534 531 555 C1' G B 7 beta 550 556 553 578 C1' A B 8 beta 573 579 576 600 C1' G B 9 beta 595 601 598 623 C1' C B 10 beta 618 624 621 643 C1' C B 11 beta 638 644 641 663 C1' G B 12 beta 658 664 661 686 C1' G B 13 beta 681 687 684 709 C1' C B 14 beta 704 710 707 729 C1' G B 15 beta 724 730 727 752 C1' A B 16 beta 747 753 750 774 C1' G B 17 beta 769 775 772 797 C1' C B 18 beta 792 798 795 817 C1' C B 19 beta 812 818 815 2653 C1' G E 1 beta 2648 2654 2651 2676 C1' G E 2 beta 2671 2677 2674 2699 C1' C E 3 beta 2694 2700 2697 2719 C1' G E 4 beta 2714 2720 2717 2742 C1' A E 5 beta 2737 2743 2740 2764 C1' A E 6 beta 2759 2765 2762 2786 C1' G E 7 beta 2781 2787 2784 2809 C1' A E 8 beta 2804 2810 2807 2831 C1' G E 9 beta 2826 2832 2829 2854 C1' C E 10 beta 2849 2855 2852 2874 C1' C E 11 beta 2869 2875 2872 2894 C1' G E 12 beta 2889 2895 2892 2917 C1' G E 13 beta 2912 2918 2915 2940 C1' C E 14 beta 2935 2941 2938 2960 C1' G E 15 beta 2955 2961 2958 2983 C1' A E 16 beta 2978 2984 2981 3005 C1' G E 17 beta 3000 3006 3003 3028 C1' C E 18 beta 3023 3029 3026 3048 C1' C E 19 beta 3043 3049 3046 3066 C1' G F 1 beta 3061 3067 3064 3089 C1' G F 2 beta 3084 3090 3087 3112 C1' C F 3 beta 3107 3113 3110 3132 C1' G F 4 beta 3127 3133 3130 3155 C1' A F 5 beta 3150 3156 3153 3177 C1' A F 6 beta 3172 3178 3175 3199 C1' G F 7 beta 3194 3200 3197 3222 C1' A F 8 beta 3217 3223 3220 3244 C1' G F 9 beta 3239 3245 3242 3267 C1' C F 10 beta 3262 3268 3265 3287 C1' C F 11 beta 3282 3288 3285 3307 C1' G F 12 beta 3302 3308 3305 3330 C1' G F 13 beta 3325 3331 3328 3353 C1' C F 14 beta 3348 3354 3351 3373 C1' G F 15 beta 3368 3374 3371 3396 C1' A F 16 beta 3391 3397 3394 3418 C1' G F 17 beta 3413 3419 3416 3441 C1' C F 18 beta 3436 3442 3439 3461 C1' C F 19 beta 3456 3462 3459 --------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------- Seq No Atom Residue Deoxyribose Ribose C1' C3' H2'1 H2'2 H2' O2' H2'1 H2'2 H2' O2' --------------------------------------------------------------------------------------------------------------------- 7 C2' G A 1 OK 9 5 8 30 C2' G A 2 OK 32 28 31 53 C2' C A 3 OK 55 51 54 73 C2' G A 4 OK 75 71 74 96 C2' A A 5 OK 98 94 97 118 C2' A A 6 OK 120 116 119 140 C2' G A 7 OK 142 138 141 163 C2' A A 8 OK 165 161 164 185 C2' G A 9 OK 187 183 186 208 C2' C A 10 OK 210 206 209 228 C2' C A 11 OK 230 226 229 248 C2' G A 12 OK 250 246 249 271 C2' G A 13 OK 273 269 272 294 C2' C A 14 OK 296 292 295 314 C2' G A 15 OK 316 312 315 337 C2' A A 16 OK 339 335 338 359 C2' G A 17 OK 361 357 360 382 C2' C A 18 OK 384 380 383 402 C2' C A 19 OK 404 400 403 420 C2' G B 1 OK 422 418 421 443 C2' G B 2 OK 445 441 444 466 C2' C B 3 OK 468 464 467 486 C2' G B 4 OK 488 484 487 509 C2' A B 5 OK 511 507 510 531 C2' A B 6 OK 533 529 532 553 C2' G B 7 OK 555 551 554 576 C2' A B 8 OK 578 574 577 598 C2' G B 9 OK 600 596 599 621 C2' C B 10 OK 623 619 622 641 C2' C B 11 OK 643 639 642 661 C2' G B 12 OK 663 659 662 684 C2' G B 13 OK 686 682 685 707 C2' C B 14 OK 709 705 708 727 C2' G B 15 OK 729 725 728 750 C2' A B 16 OK 752 748 751 772 C2' G B 17 OK 774 770 773 795 C2' C B 18 OK 797 793 796 815 C2' C B 19 OK 817 813 816 2651 C2' G E 1 OK 2653 2649 2652 2674 C2' G E 2 OK 2676 2672 2675 2697 C2' C E 3 OK 2699 2695 2698 2717 C2' G E 4 OK 2719 2715 2718 2740 C2' A E 5 OK 2742 2738 2741 2762 C2' A E 6 OK 2764 2760 2763 2784 C2' G E 7 OK 2786 2782 2785 2807 C2' A E 8 OK 2809 2805 2808 2829 C2' G E 9 OK 2831 2827 2830 2852 C2' C E 10 OK 2854 2850 2853 2872 C2' C E 11 OK 2874 2870 2873 2892 C2' G E 12 OK 2894 2890 2893 2915 C2' G E 13 OK 2917 2913 2916 2938 C2' C E 14 OK 2940 2936 2939 2958 C2' G E 15 OK 2960 2956 2959 2981 C2' A E 16 OK 2983 2979 2982 3003 C2' G E 17 OK 3005 3001 3004 3026 C2' C E 18 OK 3028 3024 3027 3046 C2' C E 19 OK 3048 3044 3047 3064 C2' G F 1 OK 3066 3062 3065 3087 C2' G F 2 OK 3089 3085 3088 3110 C2' C F 3 OK 3112 3108 3111 3130 C2' G F 4 OK 3132 3128 3131 3153 C2' A F 5 OK 3155 3151 3154 3175 C2' A F 6 OK 3177 3173 3176 3197 C2' G F 7 OK 3199 3195 3198 3220 C2' A F 8 OK 3222 3218 3221 3242 C2' G F 9 OK 3244 3240 3243 3265 C2' C F 10 OK 3267 3263 3266 3285 C2' C F 11 OK 3287 3283 3286 3305 C2' G F 12 OK 3307 3303 3306 3328 C2' G F 13 OK 3330 3326 3329 3351 C2' C F 14 OK 3353 3349 3352 3371 C2' G F 15 OK 3373 3369 3372 3394 C2' A F 16 OK 3396 3392 3395 3416 C2' G F 17 OK 3418 3414 3417 3439 C2' C F 18 OK 3441 3437 3440 3459 C2' C F 19 OK 3461 3457 3460 --------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------- Seq No Atom Residue H3' O3' C4' H3' O3' C2' --------------------------------------------------------------------------------- 5 C3' G A 1 OK 3 6 7 28 C3' G A 2 OK 26 29 30 51 C3' C A 3 OK 49 52 53 71 C3' G A 4 OK 69 72 73 94 C3' A A 5 OK 92 95 96 116 C3' A A 6 OK 114 117 118 138 C3' G A 7 OK 136 139 140 161 C3' A A 8 OK 159 162 163 183 C3' G A 9 OK 181 184 185 206 C3' C A 10 OK 204 207 208 226 C3' C A 11 OK 224 227 228 246 C3' G A 12 OK 244 247 248 269 C3' G A 13 OK 267 270 271 292 C3' C A 14 OK 290 293 294 312 C3' G A 15 OK 310 313 314 335 C3' A A 16 OK 333 336 337 357 C3' G A 17 OK 355 358 359 380 C3' C A 18 OK 378 381 382 400 C3' C A 19 OK 398 401 402 418 C3' G B 1 OK 416 419 420 441 C3' G B 2 OK 439 442 443 464 C3' C B 3 OK 462 465 466 484 C3' G B 4 OK 482 485 486 507 C3' A B 5 OK 505 508 509 529 C3' A B 6 OK 527 530 531 551 C3' G B 7 OK 549 552 553 574 C3' A B 8 OK 572 575 576 596 C3' G B 9 OK 594 597 598 619 C3' C B 10 OK 617 620 621 639 C3' C B 11 OK 637 640 641 659 C3' G B 12 OK 657 660 661 682 C3' G B 13 OK 680 683 684 705 C3' C B 14 OK 703 706 707 725 C3' G B 15 OK 723 726 727 748 C3' A B 16 OK 746 749 750 770 C3' G B 17 OK 768 771 772 793 C3' C B 18 OK 791 794 795 813 C3' C B 19 OK 811 814 815 2649 C3' G E 1 OK 2647 2650 2651 2672 C3' G E 2 OK 2670 2673 2674 2695 C3' C E 3 OK 2693 2696 2697 2715 C3' G E 4 OK 2713 2716 2717 2738 C3' A E 5 OK 2736 2739 2740 2760 C3' A E 6 OK 2758 2761 2762 2782 C3' G E 7 OK 2780 2783 2784 2805 C3' A E 8 OK 2803 2806 2807 2827 C3' G E 9 OK 2825 2828 2829 2850 C3' C E 10 OK 2848 2851 2852 2870 C3' C E 11 OK 2868 2871 2872 2890 C3' G E 12 OK 2888 2891 2892 2913 C3' G E 13 OK 2911 2914 2915 2936 C3' C E 14 OK 2934 2937 2938 2956 C3' G E 15 OK 2954 2957 2958 2979 C3' A E 16 OK 2977 2980 2981 3001 C3' G E 17 OK 2999 3002 3003 3024 C3' C E 18 OK 3022 3025 3026 3044 C3' C E 19 OK 3042 3045 3046 3062 C3' G F 1 OK 3060 3063 3064 3085 C3' G F 2 OK 3083 3086 3087 3108 C3' C F 3 OK 3106 3109 3110 3128 C3' G F 4 OK 3126 3129 3130 3151 C3' A F 5 OK 3149 3152 3153 3173 C3' A F 6 OK 3171 3174 3175 3195 C3' G F 7 OK 3193 3196 3197 3218 C3' A F 8 OK 3216 3219 3220 3240 C3' G F 9 OK 3238 3241 3242 3263 C3' C F 10 OK 3261 3264 3265 3283 C3' C F 11 OK 3281 3284 3285 3303 C3' G F 12 OK 3301 3304 3305 3326 C3' G F 13 OK 3324 3327 3328 3349 C3' C F 14 OK 3347 3350 3351 3369 C3' G F 15 OK 3367 3370 3371 3392 C3' A F 16 OK 3390 3393 3394 3414 C3' G F 17 OK 3412 3415 3416 3437 C3' C F 18 OK 3435 3438 3439 3457 C3' C F 19 OK 3455 3458 3459 --------------------------------------------------------------------------------- --------------------------------------------------------------------------------- Seq No Atom Residue H4' C5' C3' H4' C5' O4' --------------------------------------------------------------------------------- 3 C4' G A 1 OK 5 2 4 26 C4' G A 2 OK 28 25 27 49 C4' C A 3 OK 51 48 50 69 C4' G A 4 OK 71 68 70 92 C4' A A 5 OK 94 91 93 114 C4' A A 6 OK 116 113 115 136 C4' G A 7 OK 138 135 137 159 C4' A A 8 OK 161 158 160 181 C4' G A 9 OK 183 180 182 204 C4' C A 10 OK 206 203 205 224 C4' C A 11 OK 226 223 225 244 C4' G A 12 OK 246 243 245 267 C4' G A 13 OK 269 266 268 290 C4' C A 14 OK 292 289 291 310 C4' G A 15 OK 312 309 311 333 C4' A A 16 OK 335 332 334 355 C4' G A 17 OK 357 354 356 378 C4' C A 18 OK 380 377 379 398 C4' C A 19 OK 400 397 399 416 C4' G B 1 OK 418 415 417 439 C4' G B 2 OK 441 438 440 462 C4' C B 3 OK 464 461 463 482 C4' G B 4 OK 484 481 483 505 C4' A B 5 OK 507 504 506 527 C4' A B 6 OK 529 526 528 549 C4' G B 7 OK 551 548 550 572 C4' A B 8 OK 574 571 573 594 C4' G B 9 OK 596 593 595 617 C4' C B 10 OK 619 616 618 637 C4' C B 11 OK 639 636 638 657 C4' G B 12 OK 659 656 658 680 C4' G B 13 OK 682 679 681 703 C4' C B 14 OK 705 702 704 723 C4' G B 15 OK 725 722 724 746 C4' A B 16 OK 748 745 747 768 C4' G B 17 OK 770 767 769 791 C4' C B 18 OK 793 790 792 811 C4' C B 19 OK 813 810 812 2647 C4' G E 1 OK 2649 2646 2648 2670 C4' G E 2 OK 2672 2669 2671 2693 C4' C E 3 OK 2695 2692 2694 2713 C4' G E 4 OK 2715 2712 2714 2736 C4' A E 5 OK 2738 2735 2737 2758 C4' A E 6 OK 2760 2757 2759 2780 C4' G E 7 OK 2782 2779 2781 2803 C4' A E 8 OK 2805 2802 2804 2825 C4' G E 9 OK 2827 2824 2826 2848 C4' C E 10 OK 2850 2847 2849 2868 C4' C E 11 OK 2870 2867 2869 2888 C4' G E 12 OK 2890 2887 2889 2911 C4' G E 13 OK 2913 2910 2912 2934 C4' C E 14 OK 2936 2933 2935 2954 C4' G E 15 OK 2956 2953 2955 2977 C4' A E 16 OK 2979 2976 2978 2999 C4' G E 17 OK 3001 2998 3000 3022 C4' C E 18 OK 3024 3021 3023 3042 C4' C E 19 OK 3044 3041 3043 3060 C4' G F 1 OK 3062 3059 3061 3083 C4' G F 2 OK 3085 3082 3084 3106 C4' C F 3 OK 3108 3105 3107 3126 C4' G F 4 OK 3128 3125 3127 3149 C4' A F 5 OK 3151 3148 3150 3171 C4' A F 6 OK 3173 3170 3172 3193 C4' G F 7 OK 3195 3192 3194 3216 C4' A F 8 OK 3218 3215 3217 3238 C4' G F 9 OK 3240 3237 3239 3261 C4' C F 10 OK 3263 3260 3262 3281 C4' C F 11 OK 3283 3280 3282 3301 C4' G F 12 OK 3303 3300 3302 3324 C4' G F 13 OK 3326 3323 3325 3347 C4' C F 14 OK 3349 3346 3348 3367 C4' G F 15 OK 3369 3366 3368 3390 C4' A F 16 OK 3392 3389 3391 3412 C4' G F 17 OK 3414 3411 3413 3435 C4' C F 18 OK 3437 3434 3436 3455 C4' C F 19 OK 3457 3454 3456 --------------------------------------------------------------------------------- --------------------------------------------------------------------------------- Seq No Atom Residue H5'1 H5'2 O5' H5'1 H5'2 C4' --------------------------------------------------------------------------------- 2 C5' G A 1 1 3 25 C5' G A 2 24 26 48 C5' C A 3 47 49 68 C5' G A 4 67 69 91 C5' A A 5 90 92 113 C5' A A 6 112 114 135 C5' G A 7 134 136 158 C5' A A 8 157 159 180 C5' G A 9 179 181 203 C5' C A 10 202 204 223 C5' C A 11 222 224 243 C5' G A 12 242 244 266 C5' G A 13 265 267 289 C5' C A 14 288 290 309 C5' G A 15 308 310 332 C5' A A 16 331 333 354 C5' G A 17 353 355 377 C5' C A 18 376 378 397 C5' C A 19 396 398 415 C5' G B 1 414 416 438 C5' G B 2 437 439 461 C5' C B 3 460 462 481 C5' G B 4 480 482 504 C5' A B 5 503 505 526 C5' A B 6 525 527 548 C5' G B 7 547 549 571 C5' A B 8 570 572 593 C5' G B 9 592 594 616 C5' C B 10 615 617 636 C5' C B 11 635 637 656 C5' G B 12 655 657 679 C5' G B 13 678 680 702 C5' C B 14 701 703 722 C5' G B 15 721 723 745 C5' A B 16 744 746 767 C5' G B 17 766 768 790 C5' C B 18 789 791 810 C5' C B 19 809 811 2646 C5' G E 1 2645 2647 2669 C5' G E 2 2668 2670 2692 C5' C E 3 2691 2693 2712 C5' G E 4 2711 2713 2735 C5' A E 5 2734 2736 2757 C5' A E 6 2756 2758 2779 C5' G E 7 2778 2780 2802 C5' A E 8 2801 2803 2824 C5' G E 9 2823 2825 2847 C5' C E 10 2846 2848 2867 C5' C E 11 2866 2868 2887 C5' G E 12 2886 2888 2910 C5' G E 13 2909 2911 2933 C5' C E 14 2932 2934 2953 C5' G E 15 2952 2954 2976 C5' A E 16 2975 2977 2998 C5' G E 17 2997 2999 3021 C5' C E 18 3020 3022 3041 C5' C E 19 3040 3042 3059 C5' G F 1 3058 3060 3082 C5' G F 2 3081 3083 3105 C5' C F 3 3104 3106 3125 C5' G F 4 3124 3126 3148 C5' A F 5 3147 3149 3170 C5' A F 6 3169 3171 3192 C5' G F 7 3191 3193 3215 C5' A F 8 3214 3216 3237 C5' G F 9 3236 3238 3260 C5' C F 10 3259 3261 3280 C5' C F 11 3279 3281 3300 C5' G F 12 3299 3301 3323 C5' G F 13 3322 3324 3346 C5' C F 14 3345 3347 3366 C5' G F 15 3365 3367 3389 C5' A F 16 3388 3390 3411 C5' G F 17 3410 3412 3434 C5' C F 18 3433 3435 3454 C5' C F 19 3453 3455 --------------------------------------------------------------------------------- --------------------------------------------------------------------------------- Seq No Atom Residue O1P O2P O3' O1P O2P O5' --------------------------------------------------------------------------------- 21 P G A 2 distorted distorted 6 22 23 24 44 P C A 3 distorted distorted 29 45 46 47 64 P G A 4 OK OK 52 65 66 67 87 P A A 5 distorted distorted 72 88 89 90 109 P A A 6 distorted distorted 95 110 111 112 131 P G A 7 distorted distorted 117 132 133 134 154 P A A 8 distorted distorted 139 155 156 157 176 P G A 9 distorted distorted 162 177 178 179 199 P C A 10 distorted distorted 184 200 201 202 219 P C A 11 distorted distorted 207 220 221 222 239 P G A 12 distorted distorted 227 240 241 242 262 P G A 13 OK OK 247 263 264 265 285 P C A 14 distorted distorted 270 286 287 288 305 P G A 15 distorted distorted 293 306 307 308 328 P A A 16 distorted distorted 313 329 330 331 350 P G A 17 distorted distorted 336 351 352 353 373 P C A 18 distorted distorted 358 374 375 376 393 P C A 19 distorted distorted 381 394 395 396 434 P G B 2 distorted distorted 419 435 436 437 457 P C B 3 distorted distorted 442 458 459 460 477 P G B 4 OK OK 465 478 479 480 500 P A B 5 distorted distorted 485 501 502 503 522 P A B 6 distorted distorted 508 523 524 525 544 P G B 7 distorted distorted 530 545 546 547 567 P A B 8 distorted distorted 552 568 569 570 589 P G B 9 distorted distorted 575 590 591 592 612 P C B 10 distorted distorted 597 613 614 615 632 P C B 11 distorted distorted 620 633 634 635 652 P G B 12 distorted distorted 640 653 654 655 675 P G B 13 distorted distorted 660 676 677 678 698 P C B 14 distorted distorted 683 699 700 701 718 P G B 15 distorted distorted 706 719 720 721 741 P A B 16 distorted distorted 726 742 743 744 763 P G B 17 distorted distorted 749 764 765 766 786 P C B 18 distorted distorted 771 787 788 789 806 P C B 19 distorted distorted 794 807 808 809 2665 P G E 2 distorted distorted 2650 2666 2667 2668 2688 P C E 3 distorted distorted 2673 2689 2690 2691 2708 P G E 4 OK OK 2696 2709 2710 2711 2731 P A E 5 distorted distorted 2716 2732 2733 2734 2753 P A E 6 distorted distorted 2739 2754 2755 2756 2775 P G E 7 distorted distorted 2761 2776 2777 2778 2798 P A E 8 distorted distorted 2783 2799 2800 2801 2820 P G E 9 distorted distorted 2806 2821 2822 2823 2843 P C E 10 distorted distorted 2828 2844 2845 2846 2863 P C E 11 distorted distorted 2851 2864 2865 2866 2883 P G E 12 distorted distorted 2871 2884 2885 2886 2906 P G E 13 distorted distorted 2891 2907 2908 2909 2929 P C E 14 distorted distorted 2914 2930 2931 2932 2949 P G E 15 distorted distorted 2937 2950 2951 2952 2972 P A E 16 distorted distorted 2957 2973 2974 2975 2994 P G E 17 distorted distorted 2980 2995 2996 2997 3017 P C E 18 distorted distorted 3002 3018 3019 3020 3037 P C E 19 distorted distorted 3025 3038 3039 3040 3078 P G F 2 distorted distorted 3063 3079 3080 3081 3101 P C F 3 distorted distorted 3086 3102 3103 3104 3121 P G F 4 OK OK 3109 3122 3123 3124 3144 P A F 5 distorted distorted 3129 3145 3146 3147 3166 P A F 6 distorted distorted 3152 3167 3168 3169 3188 P G F 7 distorted distorted 3174 3189 3190 3191 3211 P A F 8 distorted distorted 3196 3212 3213 3214 3233 P G F 9 distorted distorted 3219 3234 3235 3236 3256 P C F 10 distorted distorted 3241 3257 3258 3259 3276 P C F 11 distorted distorted 3264 3277 3278 3279 3296 P G F 12 distorted distorted 3284 3297 3298 3299 3319 P G F 13 OK OK 3304 3320 3321 3322 3342 P C F 14 distorted distorted 3327 3343 3344 3345 3362 P G F 15 distorted distorted 3350 3363 3364 3365 3385 P A F 16 distorted distorted 3370 3386 3387 3388 3407 P G F 17 distorted distorted 3393 3408 3409 3410 3430 P C F 18 distorted distorted 3415 3431 3432 3433 3450 P C F 19 distorted distorted 3438 3451 3452 3453 ---------------------------------------------------------------------------------