Methionine sulfoxide reductases, enzymes that reverse the oxidation of methionine residues, have been described in a wide range of species. The reduction of the diastereoisomers of oxidized methionine is catalyzed by two different monomeric methionine sulfoxide reductases (MsrA and MsrB)…

Protein disulfide oxidoreductases (PDOs) are redox enzymes that catalyze dithioldisulfide exchange reactions. Their sequences and structure reveal the presence of two thioredoxin fold units, each of which is endowed with a catalytic site CXXC motif. PDOs are the outcome of…

To demonstrate that parsimony analysis of endemicity (PAE) can be a method implementing the panbiogeographic approach, we analyzed two data matrices of 40/38 biogeographic provinces x 148 plant species freom the Caribbean subregion of the Neotropical region, one where taxa…

Based on known data sets and maximum entropy distribution data of fern and lycopod species registered in the Yucatan Peninsula, track and parsimony analyses were undertaken to evaluate the contribution of these groups to the establishment of biogeographical relationships of…

The available sequences of genes encoding the enzymes associated with histidine biosynthesis suggest that this is an ancient metabolic pathway that was assembled prior to the diversification of the Bacteria, Archaea, and Eucarya. Paralogous duplications, gene elongation, and fusion events…

(2) the existence of homologous regions of the subunit tau of the E. coli DNA polymerase III with the simian immunodeficiency virus RT, the hepatitis B virus RT, and the beta' subunit of the E. coli RNA polymerase (McHenry et…

There is convincing paleontological evidence showing that stromatolitebuilding phototactic prokaryotes were already in existence 3.5 x 10(9) years ago. Late accretion impacts may have killed off life on our planet as late as 3.8 x 10(9) years ago. This leaves…