Obg

• Description: GTP-binding protein involved in initiation of sporulation and assembly of the 50S ribosome subunit
  
  

Gene name	obg
Synonyms
Essential	Yes
Product	GTP-binding protein
Function	ribosome assembly, may be required to stimulate activity of the phosphorelay that activates Spo0A
MW, pI	47 kDa, 4.859
Gene length, protein length	1284 bp, 428 aa
Immediate neighbours	pheB, spo0B
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: BSU27920

Phenotypes of a mutant

essential PubMed

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: Binds and hydrolyzes GTP and readily exchanges GDP for GTP

• Protein family: GTP1/OBG family (according to Swiss-Prot) Era/Obg family

• Paralogous protein(s): Era, Obg, YphC, YsxC, RbgA, YqeH, ThdF, YyaF, YnbA

Extended information on the protein

• Kinetic information:

• Domains:

Obg possesses 3 domains: A N-terminal glycine-rich domain (1–158), a GTP binding domain (159–342) and a C-terminal TGS domain (343–428). The TGS domain has no known function, but it is named for three protein families in which it is found, ThrRS, GTPase, and SpoT.

• Modification:

• Cofactor(s):

GDP, GTP and probably ppGpp

• Effectors of protein activity:

• Interactions:

Interaction with Rsb proteins.

• Localization:

Database entries

• Structure: 1LMZ, 1LNZ

• UniProt: P20964

• KEGG entry: [3]
• E.C. number:

Additional information

The biochemical analysis of bacterial and human Obg proteins combined with the structural observation of the ppGpp nucleotide within the Obg active site suggest a potential role for ppGpp modulation of Obg function in B. subtilis.

Expression and regulation

• Operon: spo0B-obg PubMed

• Sigma factor: SigA PubMed

• Regulation:

• Regulatory mechanism:

• Additional information:

Biological materials

• Mutant:

• Expression vector:
  • for expression/ purification from B. subtilis with N-terminal Strep-tag, for SPINE, in pGP380: pGP835, available in Stülke lab
  • for expression/ purification from E. coli with N-terminal His-tag, in pWH844: pGP843, available in Stülke lab

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

Labs working on this gene/protein

• Bill Haldenwang, San Antonio, USA
• Naotake Ogasawara, Nara, Japan

References

Reviews

Robert A Britton
Role of GTPases in bacterial ribosome assembly.
Annu Rev Microbiol: 2009, 63;155-76
[PubMed:19575570] [WorldCat.org] [DOI] (I p)