DNA‐dependent RNA polymerase from the extremely halophilic archaebacterium Halococcus morrhuae

Abstract

Pure and absolutely DNA‐dependent RNA polymerase has been isolated from the extremely halophilic archaebacterium, Halococcus morrhuae. It is composed of five heavy (142 000; 88 000; 73 000; 52 000; and 49 500 Da) and five small components (13 300; 11 200; 10 800; 10 500; 9 900 Da). The peptides of 49 500 Da and 52 500 Da probably represent one component in different modification states. Single‐stranded DNA shows the highest template efficiency, although archaebacterial chromosomal DNAs are efficiently transcribed. Rifampicin, streptolydigin and α‐amanitin do not inhibit transcription by this enzyme. Heparin permits elongation but not initiation of transcription. The activity of H. morrhuae RNA polymerase is strongly stimulated by glycerol and dimethylsulfoxide. Copyright © 1983, Wiley Blackwell. All rights reserved