Influence of dimethylsulfoxide on transcription by bacteriophage T3-induced RNA polymerase

✍ Scribed by Dr. H. Musielski; W. Mann; R. Laue; S. Michel

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 745 KB
• Volume: 21
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.19810210606

✦ Synopsis

Abstract

Dimethylsulfoxide (DMSO)Abbreviations used: Dimethylsulfoxide DMSO, polyvinyl sulfate PVS, nucleoside triphosphate NTP

up to 25% (v/v) does not cause irreversible alterations of T3 DNA at 42.5°C as assayed by transcription with T3‐specific RNA polymerase. The optimal temperature for the formation of polyanion‐resistant ternary complexes of the enzyme, T3 DNA, and nascent RNA chains is lowered by 12.5°C in the presence of 20% (v/v) DMSO. The same solvent concentration, however, decreases the temperature optimal for T3 RNA chain elongation by only 2.5°C, indicating that DMSO preferably affects the initiation of T3 RNA synthesis. DMSO accelerates the loss of T3‐specific RNA polymerase activity at 42.5°C. Nevertheless, the speed with which the binary complexes between the phage RNA polymerase and DNA are inactivated by heat (42.5°C) is not altered in presence of 20% (v/v) DMSO. The binding of T3‐induced RNA polymerase to T3 DNA in polyanion‐resistant ternary complexes is influenced by DMSO which makes the enzyme accessible to the inhibitory action of polyvinyl sulfate. Elongation of T3 RNA chains is slowed down by 20% (v/v) DMSO.