TopB

• Description: DNA topoisomerase III
  
  

Gene name	topB
Synonyms
Essential	no
Product	DNA topoisomerase III
Function	replication
Gene expression levels in SubtiExpress: topB
MW, pI	81 kDa, 9.879
Gene length, protein length	2181 bp, 727 aa
Immediate neighbours	lrpC, ydaJ
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 replication, DNA condensation/ segregation

The gene

Basic information

• Locus tag: BSU04260

Database entries

• BsubCyc: BSU04260

• DBTBS entry: no entry

• SubtiList entry: [1]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: ATP-independent breakage of single-stranded DNA, followed by passage and rejoining (according to Swiss-Prot)

• Protein family: prokaryotic type I/III topoisomerase family (according to Swiss-Prot)

• Paralogous protein(s): TopA, one of the two proteins has to be present for viability PubMed

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions:

• Localization:

Database entries

• BsubCyc: BSU04260

• Structure:

• UniProt: P96583

• KEGG entry: [2]

• E.C. number:

Expression and regulation

• Operon:

• Expression browser: topB PubMed

• Sigma factor:

• Regulation:

• Regulatory mechanism:

• Additional information:
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 144 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 452 PubMed

Biological materials

• Mutant:
  • BKE04260 (topB::ermC) (available at the BGSC and in Jörg Stülke's lab)

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

References

Helena B Thomaides, Ella J Davison, Lisa Burston, Hazel Johnson, David R Brown, Alison C Hunt, Jeffery Errington, Lloyd Czaplewski
Essential bacterial functions encoded by gene pairs.
J Bacteriol: 2007, 189(2);591-602
[PubMed:17114254] [WorldCat.org] [DOI] (P p)