>1K4S_1|Chain A[auth B]|5'-D(*AP*AP*AP*AP*AP*GP*AP*CP*(5IU)P*(5IU))-3'|
AAAAAGACUU
>1K4S_2|Chain B[auth C]|5'-D(*(SPT)P*GP*AP*AP*AP*AP*AP*(5IU)P*(5IU)P*(5IU)P*(5IU)P*T)-3'|
TGAAAAAUUUUT
>1K4S_3|Chain C[auth D]|5'-D(*AP*AP*AP*AP*AP*TP*(IDO)UP*(IDO)UP*(IDO)UP*(IDO)UP*CP*AP*AP*AP*GP*(IDO)UP*CP*(IDO)UP*(IDO)UP*(IDO)UP*(IDO)UP*T)-3'|
AAAAATUUUUCAAAGUCUUUUT
>1K4S_4|Chain D[auth A]|DNA topoisomerase I|Homo sapiens (9606)
KKPKNKDKDKKVPEPDNKKKKPKKEEEQKWKWWEEERYPEGIKWKFLEHKGPVFAPPYEPLPENVKFYYDGKVMKLSPKAEEVATFFAKMLDHEYTTKEIFRKNFFKDWRKEMTNEEKNIITNLSKCDFTQMSQYFKAQTEARKQMSKEEKLKIKEENEKLLKEYGFCIMDNHKERIANFKIEPPGLFRGRGNHPKMGMLKRRIMPEDIIINCSKDAKVPSPPPGHKWKEVRHDNKVTWLVSWTENIQGSIKYIMLNPSSRIKGEKDWQKYETARRLKKCVDKIRNQYREDWKSKEMKVRQRAVALYFIDKLALRAGNEKEEGETADTVGCCSLRVEHINLHPELDGQEYVVEFDFLGKDSIRYYNKVPVEKRVFKNLQLFMENKQPEDDLFDRLNTGILNKHLQDLMEGLTAKVFRTYNASITLQQQLKELTAPDENIPAKILSYNRANRAVAILCNHQRAPPKTFEKSMMNLQTKIDAKKEQLADARRDLKSAKADAKVMKDAKTKKVVESKKKAVQRLEEQLMKLEVQATDREENKQIALGTSKLNYLDPRITVAWCKKWGVPIEKIYNKTQREKFAWAIDMADEDYEF