Schnabel, R. and Thomm, Michael and Gerardy-Schahn, R. and Zillig, W. and Stetter, Karl Otto and Huet, J.
Structural homology between different archaebacterial DNA-dependent RNA polymerases analyzed by immunological comparison of their components.
The EMBO Journal 2, pp. 751-755.
The archaebacterial DNA-dependent RNA polymerases have a complex structure containing eight or more components. Immunochemical analysis shows an extensive homology between the components of the enzymes of nine different species. Two enzyme subtypes can be distinguished: that of the thermoacidophilic and/or sulfur-metabolizing archaebacteria with the composition BACDEFGHIJ and that of the methanogenic plus halophilic archaebacteria with the composition ABB'C(D).... Components B and B' of the latter subtype probably evolved by the division of the large component B of the BACD... type enzyme. The existence of the two subtypes corroborates the division of the archaebacteria into two phylogenetic main branches.