ribA [2019-07-04 13:30:38]

GTP cyclohydrolase II/ 3,4-dihydroxy-2-butanone 4-phosphate synthase

Locus: BSU23260

Isoelectric point: 5.58

Molecular weight: 43.96 kDa

Protein length: 398 aa

Gene length: 1197 bp

Function: riboflavin biosynthesis

Product: GTP cyclohydrolase II/ 3,4-dihydroxy-2-butanone 4-phosphate synthase

Essential: no

E.C.: 3.5.4.25

Synonyms

Genomic Context

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Categories containing this gene/protein

• Metabolism → Additional metabolic pathways → Biosynthesis of cofactors → Biosynthesis/ acquisition of riboflavin/ FAD

Gene

Coordinates: 2,428,389 → 2,429,585

The protein

Catalyzed reaction/ biological activity

• D-ribulose 5-phosphate = formate L-3,4-dihydroxybutan-2-one 4-phosphate (according to Swiss-Prot)

Structure

• 2BZ0 (from E. coli, 54% identity, 69% similarity to the C-terminal domain) PubMed

Expression and Regulation

Operons

• Genes: ribD-ribE-ribA-ribH-ribT
  Description: PubMed

  Sigma factors

  • SigA: sigma factor, PubMed, in SigA regulon

  Regulatory mechanism

  • FMN-box: transcription termination, via FMN-box in the presence of FMN or FMNH₂, this is counter-acted upon binding of RibR, in FMN-box

  Regulation

  • expressed in the absence of FMN (FMN-box) PubMed
  • binding of FMN to the FMN-box RNA is facilitated by NusG-mediated transcription pausing PubMed
  • the FMN-box RNA is degraded by RNase Y PubMed

Biological materials

Mutant

• BKE23260 (ΔribA::erm trpC2) available at BGSC, PubMed, upstream reverse: _UP1_ATGAAACATGCAAATCTTCC, downstream forward: _UP4_TAATCACAAATATCACAAAA
• BKK23260 (ΔribA::kan trpC2) available at BGSC, PubMed, upstream reverse: _UP1_ATGAAACATGCAAATCTTCC, downstream forward: _UP4_TAATCACAAATATCACAAAA

References

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