Purinosome

[1] Several individual enzymatic functions have consolidated onto single bifunctional or trifunctional polypeptide chains in higher organisms, suggesting stable physical interactions exist between enzymes.

The human purinosome was thought to have been identified in 2008 by the observation that transiently expressed GFP fusion constructs of purine biosynthesis proteins form macrobodies.

[14] Curiously, hypoxanthine levels do not alter purinosome macrobodies,[14] but adenosine or guanosine addition suppresses formation of macromolecular bodies formed by the folate enzyme.

Inhibition of microtubule polymerization with nocodazole blocks formation of the purinosome macrobodies, and reduces the flux of de novo purine biosynthesis.

Partial inhibition of casein kinase 2 by small molecule inhibitors - 4,5,6,7-tetrabromo-1H-benzimidazole (TBI), 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT), tetrabromocinammic acid (TBCA) or ellagic acid - was found to induce purinosome macrobody formation, while another inhibitor, 4,5,6,7-tetrabromobenzotriazole (TBB) induced purinosome macrobody formation at low concentration but not at high concentration, and caused the dissociation of the bodies formed in response to DMAT.

Diagram of the synthesis of IMP
enzymes
coenzymes
substrate names
metal ions
inorganic molecules
Macrobodies composed of purinosome members .
Purine biosynthesis enzymes cluster into discrete intracellular bodies when transiently expressed as fusions to enhanced green fluorescent protein ( EGFP ) in HeLa cells. [ 13 ] FGAMS is an alternate name for PFAS.