qoxB

cytochrome aa3 quinol oxidase (subunit I)

Locus: BSU_38160

Isoelectric point: 8.85

Molecular weight: 73.66 kDa

Protein length: 649 aa

Gene length: 1950 bp

Function: respiration

Product: cytochrome aa3 quinol oxidase (subunit I)

Essential: no

E.C.: 1.10.3.-

Synonyms: ipa-38d

Genomic Context

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Categories containing this gene/protein

• Metabolism → Electron transport and ATP synthesis → Respiration → Terminal oxidases
• Groups of genes → Membrane proteins

Gene

Coordinates: 3,915,319 → 3,917,268

Phenotypes of a mutant

• inactivation of qoxB restores beta-lactam resistance in a sigM mutant PubMed
• inactivation of qoxB facilitates without a wall (due to reduction of oxidative stress) PubMed

The protein

Catalyzed reaction/ biological activity

• 2 quinol + O₂ --> 2 quinone + 2 H₂O (according to UniProt)

Protein family

• heme-copper respiratory oxidase family (with CtaD, according to UniProt)

Paralogous protein(s)

• CtaD

Cofactors

• Cu(B) PubMed

Structure

• 1FFT (QoxA-QoxB-QoxC complex from E. coli, 52% identity) PubMed

Localization

• cell membrane PubMed

Expression and Regulation

Operons

• Genes: qoxA-qoxB-qoxC-qoxD
  Description: PubMed

  Regulatory mechanism

  • stringent response: negative regulation, in stringent response
  • CitB: mRNA binding, in CitB regulon

  Regulation

  • RelA dependent downregulation (Class I) during stringent response PubMed

  Additional information

  • the presence of an iron-responsive element bound by CitB between feuA and feuB suggests iron-dependent regulation by CitB PubMed

Biological materials

Mutant

• BKE38160 (ΔqoxB::erm trpC2) available at BGSC, PubMed, upstream reverse: _UP1_CATGCAGGCTTCCTCCTTTC, downstream forward: _UP4_ATTTCCGAATAAGGAGGCGT
• BKK38160 (ΔqoxB::kan trpC2) available at BGSC, PubMed, upstream reverse: _UP1_CATGCAGGCTTCCTCCTTTC, downstream forward: _UP4_ATTTCCGAATAAGGAGGCGT

References

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