Multidrug Resistance ABC Transporter ATP-Binding/Permease Protein Bmra (bmrA) Bacillus Subtilis Recombinant Protein

Function: An efflux transporter able to transport Hoechst 33342, ethidium bromide, doxorubicin and a number of other drugs in vitro into inside out vesicles. The endogenous substrate is unknown. It has been suggested that NBD dimerization induced by ATP-binding causes a large conformational change responsible for substrate translocation (Ref.10). Transmembrane domains (TMD) form a pore in the inner membrane and the ATP-binding domain (NBD) is responsible for energy generation

Probable.

Enzyme regulation: 50% inhibited by vanadate; it has been suggested that vanadate fully inhibits the dimer but not the monomer (Ref.7). Activated by 15 µM reserpine then inhibited by higher concentrations.

Subunit structure: Homodimer. Ref.4 Ref.7 Ref.9

Subcellular location: Cell membrane; Multi-pass membrane protein

Probable.

Domain: In BmrA the ATP-binding domain (NBD) and the transmembrane domain (TMD) are fused. This is considered to be a half-size transporter that undergoes homodimerization to be functional.

Disruption phenotype: Not essential. Ref.6

Sequence similarities: Belongs to the ABC transporter superfamily.Contains 1 ABC transmembrane type-1 domain.Contains 1 ABC transporter domain.

Biophysicochemical propertiesKinetic parameters:Reconstituted in proteoliposomes, Ref.5.Vmax=6.5 µmol/min/mg enzyme for ATP Ref.3 Ref.5pH dependence:Optimum pH is 8.0.