NTPs in the proteins world; their prevalence & preference

Nucleoside triphosphates (NTPs) have been considered as important contributors of the metabolicsystems of the cells. These molecules specifically function in the activation of proteins and supplying theenergy need for many essential cell functions. Although, mostly all types of NTPs are functional but,there is an special emphasize on adenosine triphosphate (ATP) as the universal energy currency of the cell[1,2]. Nevertheless, the evolutionary reason of the selection of ATP among other NTPs has not beenunderstood. This study aims to give some clues to shed light on the rationality of natural selection of ATPfor is missions. by paying attention to the NTP binding pocket in the selected enzymes (through dockingprotocols). According to the results of comparing the NTP binding pockets of enzymes using differentNTPs (ATP, GTP, CTP, UTP) it is noticeable that the ATP binding pockets tend to be less specific thanother types. This matter is concluded regarding to the comparison of the free energy of binding of theNTP (ATP had the least free energy of binding), the variety of amino-acids in the pocket (ATP bindingpockets had more diverse amino-acids), and the part of NTP from which it connects to the enzyme (ATPattaches significantly more by its phosphate groups rather than the adenosine head). It is suggestable thatthis non-specificity of ATP binding could work as an evolutionary advantage for ATP using a broadrange of proteins with different binding pockets while other NTPs couldn’t and failed to do in a similarway.

کلیدواژه ها:

Nucleotide triphosphate ، Binding pocket ، Docking protocol ، evolutionary aspect