Structural homology between different archaebacterial DNA-dependent RNA polymerases analyzed by immunological comparison of their components.
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.
Schnabel
R
R
Max-Planck-Institut für Biochemie, 8033 Martinsried bei München, FRG.
Thomm
M
M
Gerardy-Schahn
R
R
Zillig
W
W
Stetter
K O
KO
Huet
J
J