Biotin synthase (BioB), , catalyses the last step of the biotin biosynthetic pathway. The reaction consists in the introduction of a sulphur atom into dethiobiotin. BioB functions as a homodimer (PUBMED:12482614). Thiamin synthesis if a complex process involving at least six gene products (ThiFSGH, ThiI and ThiJ). Two of the proteins required for the biosynthesis of the thiazole moiety of thiamine (vitamin B(1)) are ThiG and ThiH (this entry) and form a heterodimer(PUBMED:12650933). Both of these reactions are thought of involve the binding of co-factors, and both function as dimers (PUBMED:12482614), (PUBMED:12650933). This domain therefore may be involved in co-factor binding or dimerisation.
This domain is found in biotin synthase and 2-iminoacetate synthase. The latter enzyme is involved in thiamine diphosphate biosynthesis. The reactions catalysed by these enzymes involve the binding of co-factors and both enzymes function as dimers [ (PUBMED:12482614) (PUBMED:12650933) ]. This domain may therefore be involved in co-factor binding or dimerisation. The domain is also found in proteins that are currently uncharacterised, such as Q58195 .
Family alignment:
There are 20794 BATS domains in 20792 proteins in SMART's nrdb database.
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Evolution (species in which this domain is found)
Taxonomic distribution of proteins containing BATS domain.
This tree includes only several representative species. The complete taxonomic breakdown of all proteins with BATS domain is also avaliable.
Click on the protein counts, or double click on taxonomic names to display all proteins containing BATS domain in the selected taxonomic class.
Thiamine biosynthesis in Escherichia coli: isolation and initialcharacterisation of the ThiGH complex.
FEBS Lett. 2003; 539: 95-9
Display abstract
In Escherichia coli, two of the proteins required for the biosynthesis ofthe thiazole moiety of thiamine (vitamin B(1)) are ThiG and ThiH, encodedas part of the thiCEFSGH operon. In this study, a C-terminallyhexahistidine-tagged ThiH (ThiH-His) was expressed in E. coli as a solubleprotein from thiGH-His-tag and thiFSGH-His-tag-bearing plasmids. Whenisolated under anaerobic conditions, ThiG and ThiH-His co-purify as alarge multimeric non-covalent complex. Electron paramagnetic resonance andUV-visible spectroscopy together with iron and sulfide analyses revealedthe presence of an iron-sulfur cluster within this complex.
The PLP-dependent biotin synthase from Escherichia coli: mechanisticstudies.
FEBS Lett. 2002; 532: 465-8
Display abstract
Biotin synthase (BioB), an iron-sulfur enzyme, catalyzes the last step ofthe biotin biosynthesis pathway. The reaction consists in the introductionof a sulfur atom into two non-activated C-H bonds of dethiobiotin.Substrate radical activation is initiated by the reductive cleavage ofS-adenosylmethionine (AdoMet) into a 5'-deoxyadenosyl radical. Therecently described pyridoxal 5'-phosphate-bound enzyme was used to showthat only one molecule of AdoMet, and not two, is required for theformation of one molecule of biotin. Furthermore 5'-deoxyadenosine, aproduct of the reaction, strongly inhibited biotin formation, anobservation that may explain why BioB is not able to make more than oneturnover. However this enzyme inactivation is not irreversible.
Metabolism (metabolic pathways involving proteins which contain this domain)
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This information is based on mapping of SMART genomic protein database to KEGG orthologous groups. Percentage points are related to the number of proteins with BATS domain which could be assigned to a KEGG orthologous group, and not all proteins containing BATS domain. Please note that proteins can be included in multiple pathways, ie. the numbers above will not always add up to 100%.