SigL

• Description: sigma factor of the RNA polymerase, Sigma-54, Sigma L
  
  

Gene name	sigL
Synonyms
Essential	no
Product	RNA polymerase sigma-54 factor (sigma-L)
Function	utilization of arginin, acetoin and fructose, required for cold adaptation
MW, pI	49,5 kDa, 7.79
Gene length, protein length	1308 bp, 436 amino acids
Immediate neighbours	yvfH, yvfG
Get the DNA and protein sequences (Barbe et al., 2009)
Genetic context This image was kindly provided by SubtiList

The gene

Basic information

• Locus tag: BSU34200

Phenotypes of a mutant

The mutant is cold-sensitive and unable to use arginine as a single carbon source. PubMed

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: Binding to promoters of the -12, -24 type

• Protein family: sigma-54 factor family (according to Swiss-Prot) sigma-54 factor family

• Paralogous protein(s):

Genes/ operons controlled by SigL

acoA-acoB-acoC-acoL, rocA-rocB-rocC, rocD-rocE-rocF, rocG, levD-levE-levF-levG-sacC, ptb-bcd-buk-lpdV-bkdAA-bkdAB-bkdB

Transcription factors activating transcription at SigL-dependent promoters

AcoR, BkdR, LevR, RocR, YplP

Extended information on the protein

• Kinetic information:

• Domains:
  • DNA binding domain (H-T-H motif) (324–343)
  • pron box domain (413–421)
  • 3 x Compositional bias domain (6–21),(32–53),(112–136)

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions: SigL-AcoR, SigL-RocR, SigL-LevR, SigL-BkdR, SigL-YplP, SigL-RpoB-RpoC-RpoA

• Localization:

Database entries

• Structure:

• UniProt: P24219

• KEGG entry: [3]

Additional information

Transcription initiation by SigL-containing RNA polymerase requires the activity of ATP-hydrolyzing transcription activators.

Transcription factors activating transcription at SigL-dependent promoters

Expression and regulation

• Operon: sigL (according to DBTBS)

• Sigma factor:

• Regulation: repressed by glucose (CcpA) PubMed

• Regulatory mechanism: CcpA: transcription repression, transcriptional roadblock PubMed

• Additional information:

Biological materials

• Mutant: GP146 (aphA3), available in Stülke lab

• Expression vector:

• lacZ fusion:

• GFP fusion:

• Antibody:

Labs working on this gene/protein

Michel Debarbouille, Pasteur Institute, Paris, France Homepage

References

Reviews

M Buck, M T Gallegos, D J Studholme, Y Guo, J D Gralla
The bacterial enhancer-dependent sigma(54) (sigma(N)) transcription factor.
J Bacteriol: 2000, 182(15);4129-36
[PubMed:10894718] [WorldCat.org] [DOI] (P p)

M J Merrick
In a class of its own--the RNA polymerase sigma factor sigma 54 (sigma N).
Mol Microbiol: 1993, 10(5);903-9
[PubMed:7934866] [WorldCat.org] [DOI] (P p)