The novo purine biosynthesis proceeds by two divergent paths. In bacteria, yeasts, and plants, 5-aminoimidazole ribonucleotide (AIR) is converted to 4-carboxy-AIR (CAIR) by two enzymes: N5-carboxy-AIR (N5-CAIR) synthetase (PurK) and N5-CAIR mutase (class I PurE). In animals, the conversion of AIR to CAIR requires a single enzyme, AIR carboxylase (class II PurE) []. Class I and class II PurEs are mechanistically related but bind different substrates. In yeast and plants PurE is found in PurK-class I PurE fusion proteins, known as ADE2 [, ], while animal class II PurEs are found in PurC-PurE fusion proteins, also known as ADE2 or PAICS [].
The novo purine biosynthesis proceeds by two divergent paths. In bacteria, yeasts, and plants, 5-aminoimidazole ribonucleotide (AIR) is converted to 4-carboxy-AIR (CAIR) by two enzymes: N5-carboxy-AIR (N5-CAIR) synthetase (PurK) and N5-CAIR mutase (class I PurE). In animals, the conversion of AIR to CAIR requires a single enzyme, AIR carboxylase (class II PurE) []. Class I and class II PurEs are mechanistically related but bind different substrates. In yeast and plants PurE is found in PurK-class I PurE fusion proteins, known as ADE2 [, ], while animal class II PurEs are found in PurC-PurE fusion proteins, also known as ADE2 or PAICS []. This entry represents a class II PurE domain found in ADE2 fusion proteins from animals. It is also found in some bacteria, such as Treponema denticola. This spirochete dental pathogen lacks a purK gene and contains a class II purE gene [].
The novo purine biosynthesis proceeds by two divergent paths. In bacteria, yeasts, and plants, 5-aminoimidazole ribonucleotide (AIR) is converted to 4-carboxy-AIR (CAIR) by two enzymes: N5-carboxy-AIR (N5-CAIR) synthetase (PurK) and N5-CAIR mutase (class I PurE). In animals, the conversion of AIR to CAIR requires a single enzyme, AIR carboxylase (class II PurE) []. Class I and class II PurEs are mechanistically related but bind different substrates. In yeast and plants PurE is found in PurK-class I PurE fusion proteins, known as ADE2 [, ], while animal class II PurEs are found in PurC-PurE fusion proteins, also known as ADE2 or PAICS []. This domain represents the class I PurE which is a N5-carboxyaminoimidazole ribonucleotide mutase [].
