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: