3,4-dihydroxy-2-butanone 4-phosphate synthase, RibB (IPR000422)

Short name: DHBP_synthase_RibB

Overlapping homologous superfamilies

Family relationships



3,4-dihydroxy-2-butanone 4-phosphate synthase (EC: (DHBP synthase) (RibB) catalyses the conversion of D-ribulose 5-phosphate to formate and 3,4-dihydroxy-2-butanone 4-phosphate, the latter serving as the biosynthetic precursor for the xylene ring of riboflavin [PMID: 9211332]. In Photobacterium leiognathi, the riboflavin synthesis genes ribB (DHBP synthase), ribE (riboflavin synthase), ribH (lumazone synthase) and ribA (GTP cyclohydrolase II) all reside in the lux operon [PMID: 11396941]. RibB is sometimes found as a bifunctional enzyme with GTP cyclohydrolase II that catalyses the first committed step in the biosynthesis of riboflavin (IPR000926). No sequences with significant homology to DHBP synthase are found in the metazoa.

GO terms

Biological Process

GO:0009231 riboflavin biosynthetic process

Molecular Function

GO:0008686 3,4-dihydroxy-2-butanone-4-phosphate synthase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.