Ecogene: EG12725. higB.
Pfam: PF09907 (HigB_toxin)
Co-evolution data: P64578
Function (from Uniprot):
- Toxic component of a toxin-antitoxin (TA) module. A probable translation-dependent mRNA interferase. Overexpression causes cessation of cell growth and inhibits cell proliferation via inhibition of translation; this blockage is overcome by subsequent expression of antitoxin HigA. Overexpression causes cleavage of a number of mRNAs in a translation-dependent fashion, suggesting this is an mRNA interferase.
|Note from Sergey:
- I'm working on making a model for HigA from ecoli: The crystal structure of E. coli CFT073 YddM has been determined (PDB 2ICP AND 2ICT) but it is identical (94/94) to the YddM sequence of MG1655; the YddM structure is misidentified as the structure of the related paralog HigA antitoxin (Arbing, 2010).
|Notes (from PFAM):
- HigAB antitoxin system was discovered in E. coli experimentally. They are assigned to Type II AT system from function, and The earlier known case is a RelEB system -- and that's how they are categorized as "RelEB like". HigA (antitoxin) and HigB complex from other organism is known and has a crystal structure of the complex (4MCT). This HigB belongs in a different pfam with no known structure homolog, and appears to not be a circularly permuted version of the known HigB.
- the toxin-antitoxin system usually exist in one operon, and the genes are next to each other.
- All Type II AT system are mRNA interferases -- it autoinhibits by cutting up RNA.
- The paper that describes the discovery. they cloned the genes to show that they are toxin-antitoxin.
- Christensen-Dalsgaard M, Jorgensen MG, Gerdes K;, Mol Microbiol. 2010;75:333-348.: Three new RelE-homologous mRNA interferases of Escherichia coli differentially induced by environmental stresses. PUBMED:19943910 EPMC:19943910