Disease relevance of bioH

• The bioI gene encodes a protein with similarity to cytochrome P-450s and was able to complement mutations in either bioC or bioH of E. coli [1].
• The Serratia marcescens bioH gene encodes an esterase [2].
• To investigate this further, we have overexpressed and purified the bioH gene products from both E. coli (BIOH EC) and Neisseria meningitis (BIOH NM) in E. coli [3].

High impact information on bioH

• Various nonorthologous substitutes of the bioC-coupled gene bioH from E. coli, observed in several genomes, possibly represent the existence of different pathways for pimeloyl-CoA biosynthesis [4].
• Nucleotide sequence of the bioH gene of Escherichia coli [5].
• The 104-kDa protein can be converted to the 82-kDa protein upon incubation with Fe3+ and S2-. The bioB gene product we have isolated is active in the conversion of dethiobiotin to biotin in vitro in the presence of NADPH, AdoMet, Fe3+ or Fe2+, and additional unidentified factors from the crude extracts of E. coli [6].
• Interestingly, the ORF was 70% identical to a product of the E. coli bioH gene, which lies at a locus separated from the bioABFCD operon and acts in the early steps of the biotin synthetic pathway before pimeloyl-CoA synthesis [2].
• Although the enzymatic function of BioH is not yet elucidated, the bioH gene products from S. marcescens and E. coli show esterase activity, which may imply the hydrolysis of a precursor leading to pimeloyl-CoA ester [2].

Chemical compound and disease context of bioH

• A combination of bioW and bioF allows an efficient complementation of E. coli bioC and bioH mutants, provided that pimelate is added to the biotin-depleted growth medium [7].
• To investigate the conversion of dethiobiotin to biotin in the plant kingdom, the cDNA encoding the bioB gene product equivalent from Arabidopsis thaliana was used to construct an E. coli overexpression strain [8].

Biological context of bioH

• Although several open reading frames with significant similarities to genes required for synthesis of biotin in gram-positive and gram-negative bacteria were found, only bioB, bioF, and bioH were demonstrably functional in complementation tests with known E. coli mutants [9].
• One gene, bioH, which is not present in the bioABFCD operon, is required for the synthesis of pimeloyl-CoA but its exact role in formation of this intermediate is unknown [3].
• We constructed the plasmid pTTB151 in which the E. coli bioB gene was expressed under the control of the tac promoter [10].

Associations of bioH with chemical compounds

• Eleven biotin biosynthetic genes have been identified in Kurthia sp. Kurthia sp. has two genes coding for KAPA synthase, bioF and bioFII, and also has two genes coding for BioH protein, bioH and bioHII [11].
• Our results suggest that an unidentified enzyme(s) besides the bioB gene product is obligatory for the conversion of dethiobiotin to biotin [10].

Enzymatic interactions of bioH

• Biotin synthase catalyses the final step in the biotin biosynthetic pathway and is encoded by the bioB gene in Escherichia coli [8].

Other interactions of bioH

• The B. sphaericus bioD and bioA genes were unambiguously identified within the 4.3-kb insert and shown to be closely linked to bioY (coding for a protein with a presently unknown function) and to bioB [Ohsawa et al., Gene 80 (1989) 39-48] [7].
• In Escherichia coli, biotin synthase is coded for by bioB gene [12].

References