核酶 催化RNA切割和RNA剪接 XXXXXXXXXXX GUC XXXXXXXXXXXX aaaaaaaa 3 ●●··●●●·●●●●● ●●●●··●●·● 3 YYYYYYYYYYYCAYYYYYYYYYYYY5 AC CoG AllU Catalytic mpone Recognition GC sequences GU核 酶 17 催化RNA切割和RNA剪接 Recognition sequences