ParB

• Description: chromosome positioning near the pole and transport through the polar septum / antagonist of ParA-dependent inhibition of sporulation initiation, traps DNA loops, required for the recruitment of the SMC complex to the origin of replication
  
  

Gene name	parB
Synonyms	spo0J, spo0JB
Essential	no
Product	site-specific DNA-binding protein
Function	chromosome positioning before asymmetric septation, specifying its orientation, and imposing directionality on its subsequent transport through the septum; required for sporulation (antagonist of Soj-dependent inhibition of sporulation initiation)
Gene expression levels in SubtiExpress: parB
Interactions involving this protein in SubtInteract: ParB
MW, pI	32 kDa, 8.417
Gene length, protein length	846 bp, 282 aa
Immediate neighbours	yyaC, parA
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

DNA condensation/ segregation, sporulation/ other

This gene is a member of the following regulons

Spo0A regulon

The gene

Basic information

• Locus tag: BSU40960

Database entries

• BsubCyc: BSU40960

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity:
  • inhibits ParA dimerization and concomitant DNA-binding activity by stimulating ParA ATPase activity PubMed
  • recruits the condensin complex to the DNA origin region PubMed
  • the dimer binds specifcally to the centromere-like parS sequence PubMed

• Protein family: parB family (according to Swiss-Prot)

• Paralogous protein(s): Noc

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactors:

• Effectors of protein activity:

• Interactions:
  • forms dimers PubMed
  • ParA-ParB PubMed

• Localization:
  • chromosome centromer PubMed

Database entries

• BsubCyc: BSU40960

• Structure: 4UMK (complex with parS DNA)

• UniProt: P26497

• KEGG entry: [3]

• E.C. number:

Expression and regulation

• Operon: parA-parB PubMed

• Expression browser: parB PubMed

• Sigma factor:

• Regulation:
  • repressed under conditions that trigger sporulation (Spo0A) PubMed

• Regulatory mechanism:
  • Spo0A: transcription repression PubMed

• Additional information:
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 341 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 362 PubMed
  • number of protein molecules per cell: 880 (equivalent to 440 dimers) PubMed

Biological materials

• Mutant:
  • 1S135 ( spo0J::spec), PubMed, available at BGSC
  • 1S136 ( spo0J::spec), PubMed, available at BGSC
  • 1S137 ( spo0J::spec), PubMed, available at BGSC

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

Labs working on this gene/protein

• Heath Murray, Centre for Bacterial Cell Biology, Newcastle, UK homepage