Disease relevance of sbmA

• Identification, mapping, cloning and characterization of a gene (sbmA) required for microcin B17 action on Escherichia coli K12 [1].
• The function of the Rhizobium meliloti bacA gene, which is a homolog of the Escherichia coli sbmA gene, is required for an intermediate step in nodule development [2].

High impact information on sbmA

• Southern blotting experiments indicate that a gene closely related to bacA/sbmA is found in many bacteria, including some that invade eukaryotic cells [3].
• When expressed in E. coli with the lacZ promoter, the R. meliloti bacA gene was found to suppress all the known defects of E. coli sbmA mutants, namely, increased resistance to microcin B17, microcin J25, and bleomycin, demonstrating the functional similarity between the two proteins [4].
• Phenotypic and mapping studies showed the mutations to be located in the fhuA, exb, tonB, and sbmA genes [5].
• Several-base-pair insertions into the positions between sbyA and sbmA affected the frequency of transfer in a manner dependent upon the number of base pairs, indicating that the phasing between sbyA and sbmA is important [6].
• The region seems to contain four core binding sites (designated sbmA, sbmB, sbmC, and sbmD), each consisting of a similar number of nucleotides and including a homologous 15-bp sequence [7].

Biological context of sbmA

• The wild-type sbmA allele was cloned into multiple copy number plasmids, and its location within the cloned DNA fragment was further defined by mutagenesis with MiniMudII1681 [1].
• Plasmids carrying these gene fusions produced low levels of beta-galactosidase, indicating that the sbmA gene is poorly expressed [1].
• The mutations in these strains were mapped to a gene (sbmA), located at 8.7 min on the E. coli K12 chromosome, which is closely linked to phoA [1].

Other interactions of sbmA

• These insertion mutations resulted in in-frame fusions between the sbmA and lacZ genes, thereby allowing us to determine the direction of sbmA gene transcription [1].

References