ATPase
Noun
Meaning
ATPase (plural ATPases)
(biochemistry) A type of enzyme which works to convert adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and a free phosphate ion, thereby releasing energy to be used in cellular activity.
Synonyms
Examples
ATP hydrolysis occurs in the globular head domains, which share similarities with the AAA+ (ATPase associated with various cellular activities) protein family.
Each end of the core particle associates with a 19S regulatory subunit that contains multiple ATPase active sites and ubiquitin binding sites; it is this structure that recognizes polyubiquitinated proteins and transfers them to the catalytic core.
Many bacteria also possess other homologs of the proteasome and an associated ATPase, most notably ClpP and ClpX.
Only a single gene encoding the putative ATPase subunit of the terminase (UL15) is conserved among all herpesviruses.
The ATPases C-termini bind into pockets in the top of the 20S, and tether the ATPase complex to the 20S proteolytic complex, thus joining the substrate unfolding equipment with the 20S degradation machinery.