Figure 32.7 A Formation of purinosomes. A gene construct encoding a fusion protein consisting of formylglycinamidine synthase and green fluorescent protein (GFP) was transfected into Hela cells (a human cell line) and expressed in them. (A) In the presence of purines (the absence of purine synthesis), the GFP was seen as a diffuse stain throughout the cytoplasm. (B) When the cells were placed in a purine-