1999 Volume 75 Issue 3 Pages 64-69
The three types of archaebacterial ribosomal RNAs, 5S, 16S, and 23S, have been studied in terms of their closest homologues of the non-archaebacterial origin, the numbers of close homologues of eukaryotic and eubacterial organisms, and the insertion and deletion of bases. It is concluded that all the ribosomal RNAs are of eubacterial-type. In contrast, archaebacterial ribosomal proteins have been identified to compose a population that possesses characteristics of eukaryotic-type. Thus the archaebacterial ribosome is a chimera of the eubacterial-type RNAs and the eukaryotic-type proteins.