SpoIIIAH

• Description: component of the SpoIIIA-SpoIIQ type III secretion system residing in the forespore membrane, required for SigG activation
  
  

Gene name	spoIIIAH
Synonyms
Essential	no
Product	part of the transmembrane channel linking the mother cell and the forespore
Function	activation of SigG, forespore encasement by the spore coat
Gene expression levels in SubtiExpress: spoIIIAH
Interactions involving this protein in SubtInteract: SpoIIIAH
MW, pI	23 kDa, 4.627
Gene length, protein length	654 bp, 218 aa
Immediate neighbours	accB, spoIIIAG
Sequences	Protein DNA DNA_with_flanks
Genetic context This image was kindly provided by SubtiList
Expression at a glance   PubMed

Categories containing this gene/protein

protein secretion, sporulation proteins, membrane proteins

This gene is a member of the following regulons

SigE regulon, SpoIIID regulon

The gene

Basic information

• Locus tag: BSU24360

Phenotypes of a mutant

• block of sporulation after engulfment

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity:
  • required for forespore encasement by the spore coat PubMed

• Protein family:

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions:
  • SpoIIIAH-SpoIIQ (interaction between proteins membrane proteins expressed in the mother cell and the forespore, respectively; the complex forms a 60 Å channel made up of twelve subunits of each protein) PubMed

• Localization:
  • membrane protein, forms a transmembrane channel linking the mother cell and the forespore (with SpoIIQ) PubMed
  • proper recruitment to the sporulation septum on the mother cell side requires SpoIIQ PubMed

Database entries

• Structure:
  • 3UZO; 3TUF (the SpoIIQ-SpoIIIAH pore forming complex) PubMed

• UniProt: P49785

• KEGG entry: [3]

• E.C. number:

Expression and regulation

• Operon:
  • spoIIIAA-spoIIIAB-spoIIIAC-spoIIIAD-spoIIIAE-spoIIIAF-spoIIIAG-spoIIIAH PubMed
  • spoIIIAG-spoIIIAH PubMed

• Expression browser: spoIIIAH PubMed

• Sigma factor: SigE PubMed
  • both promoters: SigE PubMed

• Regulation:
  • both promoters: expressed during sporulation in the mother cell (SigE) PubMed, switched off by SpoIIID PubMed

• Regulatory mechanism: SpoIIID: transcription repression PubMed

• Additional information: the internal promoter is essential for sporulation, it is twice as active as the promoter in front of spoIIIAA, suggesting that SpoIIIAG and SpoIIIAH are required in larger amounts as compared to the other products of the operon PubMed

Biological materials

• Mutant:

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

Labs working on this gene/protein

• Charles Moran, Emory University, NC, USA homepage