| Comment |
A multisubunit non-phosphorylated ATPase that is involved in the
transport of ions. Large enzymes of mitochondria, chloroplasts and
bacteria with a membrane sector (Fo, Vo, Ao) and a
cytoplasmic-compartment sector (F1, V1, A1). The F-type enzymes of
the inner mitochondrial and thylakoid membranes act as ATP
synthases. All of the enzymes included here operate in a rotational
mode, where the extramembrane sector (containing 3 alpha- and 3
beta-subunits) is connected via the delta-subunit to the membrane
sector by several smaller subunits. Within this complex, the gamma-
and epsilon-subunits, as well as the 9-12 c subunits rotate by
consecutive 120_degree_ angles and perform parts of ATP synthesis.
This movement is driven by the H+ electrochemical potential
gradient. The V-type (in vacuoles and clathrin-coated vesicles) and
A-type (archebacterial) enzymes have a similar structure but, under
physiological conditions, they pump H+ rather than synthesize ATP. |
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