Biochemical genetics of Chinese hamster cell mutants with deviant purine metabolism: isolation and characterization of a mutant deficient in the activity of phosphoribosylaminoimidazole synthetase.
A new purine-requiring mutant of Chinese hamster ovary cells (CHO-Kl) is described. This mutant, Ade-G, grows on aminoimidazole carboxamide, hypoxanthine, or adenine. It complements all eight of our other previously described Ade- mutants. Biochemical analysis of de novo purine synthesis in whole cells suggests that Ade-G is capable of the first four reactions of de novo purine biosynthesis and that it synthesizes and accumulates phosphoribosylformylglycinamidine (FGAM). Direct enzyme assay in cell-free extracts confirms that Ade-G is defective in phosphoribosylaminoimidazole synthetase activity and does not convert FGAM to phosphoribosylaminoimidazole (AIR), the next intermediate in the de novo biosynthetic pathway.
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D005260:Female; D005816:Genetic Complementation Test; D007093:Imidazoles; D008025:Ligases / Q000235:genetics*; D009154:Mutation; D010053:Ovary; D010641:Phenotype; D011687:Purines / Q000378:metabolism; D012267:Ribosemonophosphates
D007093:Imidazoles; D011687:Purines; D012267:Ribosemonophosphates; D008025:Ligases