Clostridium thermocellum (Cth)TTM and similar proteins, a subgroup of the CYTH-like superfamily
CthTTM is a metal dependent tripolyphosphatase, nucleoside triphosphatase, and nucleoside tetraphosphatase. It hydrolyzes the beta-gamma phosphoanhydride linkage of triphosphate-containing substrates including tripolyphosphate, nucleoside triphosphates and nucleoside tetraphosphates. These substrates are hydrolyzed, releasing Pi. Mg++ or Mn++ are required for the enzyme's activity. CthTTM appears to have no adenylate cyclase activity. This subgroup consists chiefly of bacterial sequences. Members of the CYTH-like (also known as triphosphate tunnel metalloenzyme (TTM)-like) superfamily have a unique active site located within an eight-stranded beta barrel.