EVOLUTION OF TRANSLATIONAL ELONGATION-FACTOR (EF) SEQUENCES - RELIABILITY OF GLOBAL PHYLOGENIES INFERRED FROM EF-1-ALPHA(TU) AND EF-2(G) PROTEINS

The EF-2 coding genes of the Archaea Pyrococcus woesei and Desulfuroco ccus mobilis were cloned and sequenced. Global phylogenies were inferr ed by alternative tree-making methods from available EF-2(G) sequence data and contrasted with phylogenies constructed from the more conserv ed but shorter EF-1alpha(Tu) sequences. Both the monophyly (sensu Henn ig) of Archaea and their subdivision into the kingdoms Crenarchaeota a nd Euryarchaeota are consistently inferred by analysis of EF-2(G) sequ ences, usually at a high bootstrap confidence level. In contrast, EF-1 alpha(Tu) phylogenies tend to be inconsistent with one another and sho w low boot-strap confidence levels. While evolutionary distance and DN A maximum parsimony analyses of EF-1alpha(Tu) sequences do show archae al monophyly, protein parsimony and DNA maximum-likelihood analyses of these data do not. In no case, however, do any of the tree topologies inferred from EF-1alpha(Tu) sequence analyses receive significant boo tstrap support.