TnrA

• Description: transcriptional pleiotropic regulator (MerR family) involved in global nitrogen regulation
  
  

Gene name	tnrA
Synonyms	scgR
Essential	no
Product	transcription activator/ repressor (MerR family)
Function	regulation of nitrogen assimilation
Gene expression levels in SubtiExpress: tnrA
Interactions involving this protein in SubtInteract: TnrA
Metabolic function and regulation of this protein in SubtiPathways: tnrA
MW, pI	12 kDa, 10.235
Gene length, protein length	330 bp, 110 aa
Immediate neighbours	mgtE, ykzB
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

biosynthesis/ acquisition of amino acids, glutamate metabolism, transcription factors and their control, regulators of core metabolism

This gene is a member of the following regulons

GlnR regulon, TnrA regulon

The gene

Basic information

• Locus tag: BSU13310

Database entries

• BsubCyc: BSU13310

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity:

• Protein family: MerR family

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:
  • K(D) value for the binding site in the tnrA promoter region: 55 nM PubMed

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity: feedback-inhibited GlnA prevents TnrA from DNA binding

• Interactions:
  • TnrA-NrgB PubMed
  • TnrA-GlnA, this interaction results in loss of TnrA DNA-binding activity as well as in inhibition of GlnA PubMed

• Localization: membrane-associated via NrgA-NrgB under conditions of poor nitrogen supply PubMed

Database entries

• BsubCyc: BSU13310

• Structure:
  • 4R22 (the TnrA-DNA complex) PubMed
  • 4S0R (the TnrA-GlnA complex) PubMed

• UniProt: Q45666

• KEGG entry: [3]

• E.C. number:

Expression and regulation

• Operon: tnrA (according to DBTBS)

• Expression browser: tnrA PubMed

• Sigma factor:

• Regulation:
  • expression is autocativated (TnrA) and repressed by GlnR PubMed
  • expressed in the absence of good nitrogen sources (glutamine or ammonium) (TnrA) PubMed

• Regulatory mechanism:
  • TnrA: transcription activation PubMed

• Additional information:

Biological materials

• Mutant: GP252 (in frame deletion), available in the Stülke lab
  • 1A851 ( tnrA::erm), PubMed, available at BGSC
  • 1A851 ( tnrA::erm), PubMed, available at BGSC

• Expression vector:
  • for expression, purification in E. coli with N-terminal His-tag, in pWH844: pGP171 available in Stülke lab
  • pGP229 (N-terminal Strep-tag, for SPINE, expression in B. subtilis, in pGP380), available in Stülke lab

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody: available in the Karl Forchhammer lab

Labs working on this gene/protein

• Susan Fisher, Boston, USA homepage
• Maria Schumacher, Durham, NC, USA homepage

References

Reviews

Katrin Gunka, Fabian M Commichau
Control of glutamate homeostasis in Bacillus subtilis: a complex interplay between ammonium assimilation, glutamate biosynthesis and degradation.
Mol Microbiol: 2012, 85(2);213-24
[PubMed:22625175] [WorldCat.org] [DOI] (I p)

Fabian M Commichau, Jörg Stülke
Trigger enzymes: bifunctional proteins active in metabolism and in controlling gene expression.
Mol Microbiol: 2008, 67(4);692-702
[PubMed:18086213] [WorldCat.org] [DOI] (P p)

S H Fisher
Regulation of nitrogen metabolism in Bacillus subtilis: vive la différence!
Mol Microbiol: 1999, 32(2);223-32
[PubMed:10231480] [WorldCat.org] [DOI] (P p)

The TnrA regulon

Ken-ichi Yoshida, Hirotake Yamaguchi, Masaki Kinehara, Yo-hei Ohki, Yoshiko Nakaura, Yasutaro Fujita
Identification of additional TnrA-regulated genes of Bacillus subtilis associated with a TnrA box.
Mol Microbiol: 2003, 49(1);157-65
[PubMed:12823818] [WorldCat.org] [DOI] (P p)