DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. DNA-directed RNA polymerase subunit alpha RNA polymerase subunit alpha rpoA RPOA_AQUAE aq_070 Transcriptase subunit alpha 317 MLNEFIYPDKIFWEEKTDTYGRLVVEPLERGFGTTVGNSLRRVLLSSISGTAITAVKIYGIYHEFSAIEGVQEDAIELIANLKKIKFLMKGDSDVEILYLQKKGEGEVKASDIKTPPNVEILNPDQYIATITDPNKELNIEIRVERGRGYVPVEEMEAIGEVGWILVDADFSPVKKVGFRVDNVRVGKKSTYERLTLEIFTNGIKTPDQCMQEAIEILKKHYELLENIFTEKPTVPQKVAVDELAEKLSLSIEELDISQRALNSLKRIGITTIGDLVRMTEDELKSTKNIGRKALAEIKEALHKLGLELGMNIETQR