Open AccessIn vitrotranscription close to the melting point of DNA: analysis ofThermotoga maritimaRNA polymerase—promoter complexes at 75°C using chemical probes
Author(s) -
Thomas Meier,
Peter Schickor,
Andrew Wedel,
Luciano Cellai,
Hermann Heumann
Publication year - 1995
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/23.6.988
Subject(s) - biology , rna polymerase , polymerase , transcription (linguistics) , transcription bubble , microbiology and biotechnology , dna polymerase , thermotoga maritima , dna , dna polymerase ii , dna clamp , dna polymerase i , rna polymerase ii , biochemistry , promoter , escherichia coli , rna , rna dependent rna polymerase , gene expression , gene , reverse transcriptase , linguistics , philosophy
The interaction of DNA dependent RNA polymerase of the extreme thermophile bacteria Thermotoga maritima with a promoter bearing DNA fragment was investigated in the temperature range from 20 to 85 degrees C. We show that the T. maritima RNA polymerase recognizes and utilizes the Escherichia coli T7 A1 promoter with an efficiency similar to that of the E. coli polymerase. We have investigated the interaction of both polymerases with the same promoter over a wide range of temperatures using hydroxyl radical foot-printing and osmium tetroxide probing. This study revealed that the T. maritima polymerase goes through a series of isomerisation events very similar to the E. coli polymerase, i.e. the closed, intermediate and open complexes, but the transitions themselves occur at radically different temperatures. This indicates that conformational changes in the DNA that accompany initiation of transcription such as promoter melting are determined by the polymerase rather than the DNA sequence.