P035
Lysine and arginine “fingers” could replace K+ as
cofactors of phosphoester bond cleavage in the course
of evolution
Daria V. Dibrova1,2, Michael Y. Galperin3,
Eugene Koonin3 and Armen Y. Mulkidjanian1,2
1
School of Physics, University of Osnabrueck,
Osnabrueck, Germany
2
School of Bioengineering and Bioinformatics, Lomonosov
Moscow State University, Moscow, Russia
3
National Center for Biotechnology Information, NLM,
NIH, Bethesda, USA
Enzymes that catalyze cleavage of phosphoester bonds require
positive charges to stabilize the negatively charged phosphate
groups. In the case of ATPases and GTPases the necessary four
positive charges are routinely provided either by two divalent
cations or by a Mg2+ cation in combination with side chains
of lysine or arginine. Earlier, based on comparative structural
analysis, we have argued that in translation factors, the evolutionarily oldest GTPases found in all organisms, one of the positive
charges is provided by a specifically bound potassium ion [1].
Phylogenomic and structural analysis shows that, in the course of
evolution, functionally important potassium ions were apparently
replaced in GTPases, as well as in many ATPases, by arginine or
lysine residues. We suggest that the independent recruitment of
lysine and arginine “fingers”, instead of potassium ions, in many
enzyme families might enable a better control over the enzymatic
cleavage of phosphoester bonds.
References:
1. Mulkidjanian AY, Bychkov AY, Dibrova DV, Galperin MY, Koonin
EV. 2012. Origin of first cells at terrestrial, anoxic geothermal
fields. Proc Natl Acad Sci U S A. 109:E821-30.