COMPARATIVE STUDIES OF STRUCTURE AND FUNCTION OF DNA-DEPENDENT RNA POLYMERASES FROM EUBACTERIA AND ARCHAEBACTERIA

摘要: ABSTRACT DNA-dependent RNA polymerases of Eubacteria including blue green algae are the type β'.βα2σ. Recent evidence, however, raises problem homology β' and β subunits gramnegative grampositive bacteria. The small size σ factor bacteria, existence an additional subunit, fuction bacillus yield evidence for structural functional differences “σ-systems”. By use mutants affinity labelling roles have been tentatively appointed to subunits. In spite different eubacterial polymerases, function promoter recognition is strikingly similar. Eukaryotic appear similar enzymes in also containing two large Since, knowledge on structure eukaryotic very limited, a comparison cannot be made yet. Recently, we isolated from several Archaebacteria Halobacterium halobium , Sulfolobus acidocaldarius own isolate Caldariella . They both structurally (subunit pattern SDS polyacrylamide gels subunit composition) function, especially initiation, polymerases. Thus they further support regarding this group organisms third kingdom besides those Eukaryotes. Because their adaptation extreme environments either ionic strength or temperature these suitable investigation certain aspects transcription mechanism. Structure bacteria higher shall discussed.