TopA

• Description: DNA topoisomerase I
  
  

Gene name	topA
Synonyms	topI
Essential	no
Product	DNA topoisomerase I
Function	DNA replication
Gene expression levels in SubtiExpress: topA
MW, pI	78 kDa, 9.023
Gene length, protein length	2073 bp, 691 aa
Immediate neighbours	dprA, trmFO
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

This gene is a member of the following regulons

Efp-dependent proteins

The gene

Basic information

• Locus tag: BSU16120

Database entries

• BsubCyc: BSU16120

• DBTBS entry: [1]

• SubtiList entry: [2]

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): TopB, 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:
  • TopA interacts with the RNA polymerase PubMed

• Localization:

Database entries

• BsubCyc: BSU16120

• Structure:

• UniProt: P39814

• KEGG entry: [3]

• E.C. number:

Expression and regulation

• Operon: topA (according to DBTBS)

• Expression browser: topA PubMed

• Sigma factor:

• Regulation:

• Regulatory mechanism:

• Additional information:
  • translation is likely to require Efp due to the presence of several consecutive proline residues PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 324 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 1123 PubMed

Biological materials

• Mutant:

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

References

Olivier Delumeau, François Lecointe, Jan Muntel, Alain Guillot, Eric Guédon, Véronique Monnet, Michael Hecker, Dörte Becher, Patrice Polard, Philippe Noirot
The dynamic protein partnership of RNA polymerase in Bacillus subtilis.
Proteomics: 2011, 11(15);2992-3001
[PubMed:21710567] [WorldCat.org] [DOI] (I p)

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)