RIB7 notes (P33312, YBR153W)

• Function: DAROPP reductase (EC 1.1.1.302), second step of riboflavin biosynthesis [UniProt:P33312]; "In archaea and fungi, DAROPP is reduced at the phosphoribosyl moiety by RIB7 yielding 2, 5-diamino-6-ribitylamino-4(3H)-pyrimidinone 5′-phosphate (DARIPP), which is then deaminated into ... (ARIPP) by RIB2" PMID:23620735.
• Substrate preference: "ScRIB7 catalyzes reduction of DAROPP, while bacterial RibD catalyzes reduction of AROPP." Wild type also reduces AROPP in vitro but prefers DAROPP; T35K flips preference PMID:23620735.
• Structure: homodimer; NADPH complex; "A conserved G(76)-X-G(78)-Xn-G(181)-G(182) motif is present at the NADPH pyrophosphate group binding site." PMID:23620735
• Genetics: "the genes rib(1) and rib(7) code for the first and second enzyme of the riboflavine pathway, respectively." PMID:4555411 (abstract only)
• GO gap: GO:0008703 is defined on the bacterial uracil substrate (EC 1.1.1.193); no GO term for EC 1.1.1.302. Proposed new term in review.
• Localisation: no direct data; cytosol from YeastPathways RCA, no targeting signal.
• Review decisions: 7 ACCEPT, 2 MODIFY (GO:0016616 -> GO:0008703; GO:0042727 superpathway -> GO:0009231), 1 KEEP_AS_NON_CORE (NADP binding).