Sda

• Description: Sda is a checkpoint protein that is upregulated in response to replication stress (Burkholder et al 2001, Cell). Sda inhibits the autokinase activity of KinA (and likely KinB as well). This in its turn results in reduced levels of Spo0A~P. Thus, replication stressed cells will not initiate sporulation
  
  Sda is rapidly turned over by the ClpP/X system because of some uncharged residues at its C-terminus Ruvolo et al 2006, MolMic.

Gene name	sda
Synonyms
Essential	no
Product	developmental checkpoint protein
Function	mediates a developmental checkpoint coupling initiation of sporulation (phosphorylation of Spo0A) to the function of replication initiation proteins
MW, pI	6 kDa, 5.605
Gene length, protein length	156 bp, 52 aa
Immediate neighbours	yloV, sdaAA
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: BSU25690

Phenotypes of a mutant

• sporulates at a higher frequency
• will sporulate in the presence of replication stress

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity:

• Protein family:

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions: KinB-Sda, KinA-Sda

• Localization:

Database entries

• Structure: 3D36 (from Geobacillus stearothermophilus, complex with KinB), 1PV0

• UniProt: Q7WY62

• KEGG entry: [3]

• E.C. number:

Expression and regulation

• Operon: sda

• Sigma factor: SigA

• Regulation: DnaA
  • repressed when no DNA damage is present (LexA) PubMed

• Regulatory mechanism: Probably activated by DnaA under replication stress
  • LexA: transcription repression PubMed

• Additional information:

Biological materials

• Mutant:

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

Labs working on this gene/protein

Bill Burkholder http://burkholder.stanford.edu/