Molecular evolution of H+-ATPases. I. Methanococcus and Sulfolobus are monophyletic with respect to eukaryotes and Eubacteria.
The classification of methanogenic bacteria as archaebacteria based on 16 s rRNA sequence analysis is currently in dispute. To provide an alternative molecular marker, the polymerase chain reaction technique was used to amplify a 930 bp fragment of Methanococcus thermolithotrophicus genomic DNA corresponding to the catalytic domain of the membrane H+-ATPase. The deduced amino acid sequence was 54-58% identical to the approximately 70 kDa subunits of Sulfolobus acidocaldarius and the eukaryotic vacuolar-type H+-ATPase, and only 29% identical to the beta subunit of the eubacterial-type F0F1-ATPases. Interestingly, a highly conserved aspartate residue in the phosphorylation domain of E1E2-ATPases (P-type) is conserved in the Methanococcus sequence, but is absent from all other known vacuolar and F0F1-ATPases. This suggests that the H+-ATPase of M. thermolithotrophicus, like that of M. voltae, may have a phosphorylated intermediate, despite belonging to the vacuolar-type class of proton pumps. Phylogenetic analysis using Felsenstein's maximum likelihood method and Lake's evolutionary parsimony method confirmed that the H+-ATPases of the two archaebacteria, Methanococcus and Sulfolobus, when compared to eukaryotic vacuolar-type ATPases and eubacterial F0F1-ATPases, form a monophyletic group.
Gogarten
J P
JP
Biology Department, University of California, Santa Cruz 95064.
Rausch
T
T
Bernasconi
P
P
Kibak
H
H
Taiz
L
L
D000595:Amino Acid Sequence; D001105:Archaea / Q000201:enzymology* / Q000235:genetics; D001419:Bacteria / Q000201:enzymology*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005057:Eukaryotic Cells / Q000201:enzymology; D019605:Euryarchaeota / Q000201:enzymology* / Q000235:genetics; D005784:Gene Amplification; D005796:Genes; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010802:Phylogeny; D006180:Proton-Translocating ATPases / Q000235:genetics*
D004269:DNA, Bacterial; D006180:Proton-Translocating ATPases