title: Mutational analysis of the structure and function of the adenine phosphoribosyltransferase enzyme of Chinese hamster.
abstract: We have analyzed the adenine phosphoribosyltransferase (APRT) enzyme from Chinese hamster ovary cells through the study of mutants that are able to grow in the presence of the toxic adenine analogue 8-azaadenine. The distribution of the amino acid alterations was analyzed in terms of the binding regions for the purine and phosphoribosylpyrophosphate substrates and a comparison was made with mutants known in human APRT and human, mouse and hamster hypoxanthine-guanine phosphoribosyltransferase. A number of mutants were found to cluster in several regions of the amino acid sequence. Residual enzyme activity with adenine was determined and this was correlated with substrate binding regions. A model of the secondary structure features is proposed.
authors.affiliation: York University Biology Department, Downsview, Ontario, Canada.
authors.forename: J G
authors.initials: JG
authors.lastname: de Boer
authors.forename: B W
authors.initials: BW
authors.lastname: Glickman
mesh_terms: D000228:Adenine Phosphoribosyltransferase / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D006224:Cricetinae; D004252:DNA Mutational Analysis; D008969:Molecular Sequence Data; D009154:Mutation; D010754:Phosphoribosyl Pyrophosphate / Q000378:metabolism; D011487:Protein Conformation; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
chemical_list: D010754:Phosphoribosyl Pyrophosphate; D000228:Adenine Phosphoribosyltransferase