PRS3 notes (ribose-phosphate pyrophosphokinase subunit, UniProt P38689)

Gene-specific

• Major subunit with Prs1 PMID:9108276
• Pleiotropic null phenotypes (G1 arrest failure, actin, cell integrity) PMID:10514564 - not annotated in GOA; whether these are secondary to PRPP shortage is open.

PRS family evidence (shared)

• Five PRS genes; individual subunits inactive, specific pairs active in E. coli PMID:15280369
• Active pairs PMID:15280369; stable enzyme needs >=3 subunits PMID:15280369
• Genetic architecture: PMID:10212224; Y2H PMID:10212224
• PRPP use PMID:9829955
• Conserved motifs PMID:9829955
• Localization: cytoplasm by GFP [PMID:14562095; UniProt "SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:14562095}."]
• Pairwise Prs-Prs 'protein binding' IPIs (Gavin, Betel, Tarassov, Yu, Michaelis, Uetz, Ito) all reflect hetero-oligomer assembly PMID:17892321 -> REMOVE as uninformative; captured by GO:0002189.

Curation decisions (shared)

• Core: contributes_to GO:0004749 (no subunit active alone; matches SGD IGI 'contributes_to' qualifiers), GO:0006015, cytosol, in_complex GO:0002189.
• Downstream BPs (purine nucleotide biosynthesis IBA, nucleotide biosynthesis IEA/RCA from superpathway PRPP-PWY-1, ribonucleoside monophosphate biosynthesis IEA) -> KEEP_AS_NON_CORE: PRPP is a precursor; GO:0006015 is not part_of these.
• Mg2+ binding IEA -> KEEP_AS_NON_CORE (DCbs motif).