ИСТИНА

FOF1-ATP synthase is a multisubunit membrane enzyme that interconverts two main “energy currencies” of a living cell – ATP and protonmotive force. We investigated the variety of ATP synthases in prokaryotes by analyzing 711 genomes that represent the diversity of eubacteria and archaea [1]. The analysis confirmed that F-type ATP synthase is an eubacterial enzyme and is very rarely found in archaea. It was also revealed that F-type ATP synthase is absent in some eubacteria, including Spirochaetaceae, Synergistales, Acholeplasmatales, Thermales, Deinococcales. On the other hand, we found many species having two or even three different F-type ATP synthases. In most cases the additional enzymes were sodium-translocating N-type ATPases. The operon structure of F-type ATP synthase varied between different bacteria. A common case is a single operon containing genes of all subunits and of UncI protein that is involved in assembly of the FO part of the enzyme. But in some species, there are two or more (up to six!) operons coding ATP synthase subunits. We also found ATP synthase operons that contain genes coding other proteins with known function (e.g. uracil-xanthine permease, threonine efflux protein, ribonuclease R) or hypothetical proteins. One of the latter hypothetical proteins is found in several species of Flavobacteriia and Cytophagia. It is a hydrophobic protein with four transmembrane helices predicted. The corresponding gene is located between genes coding subunit a and UncI protein. We speculate this hypothetical protein, like UncI, might be involved in assembly of FO. This work was supported by the Russian Science Foundation research project №14‐14‐00128. [1] M.Y. Galperin, K.S. Makarova, Y.I. Wolf, E.V. Koonin, Expanded microbial genome coverage and improved protein family annotation in the COG database, Nucleic Acids Res. 43 (2015) D261–9.