Recombinant Bacillus subtilis Choline transport system permease protein opuBD (opuBD)
Description
Recombinant Expression and Purification
The recombinant OpuBD protein is produced in E. coli using the following parameters :
| Parameter | Details |
|---|---|
| Expression System | E. coli BL21 |
| Vector | pASK-IBA6 derivative with tet promoter |
| Tag | N-terminal His-tag |
| Purity | >90% (SDS-PAGE) |
| Storage | Lyophilized powder in Tris/PBS buffer (6% trehalose, pH 8.0) at -80°C |
| Reconstitution | Deionized water with 5–50% glycerol to prevent aggregation |
Functional Role in the OpuB Transporter
OpuBD functions as the permease component of the OpuB ABC transporter, which is part of a choline-specific import system . Key functional insights include:
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Substrate Specificity: OpuB selectively imports choline and arsenocholine but lacks affinity for glycine betaine .
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Mechanism: ATP hydrolysis by the OpuBA ATPase drives choline import, with OpuBC (a substrate-binding protein) delivering choline to the OpuBD permease .
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Osmotic Regulation: OpuB is induced under high osmolality to prioritize choline uptake for glycine betaine synthesis .
Comparative Analysis of Opu Transporters
OpuBD’s role is distinct from other B. subtilis osmoprotectant transporters:
Research Findings
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Binding Specificity: Structural studies of OpuBC (the binding protein partner) reveal choline’s trimethylammonium group interacts with an aromatic cage of tyrosine residues, while its hydroxyl group binds Gln19 . Mutating Gln19 reduces choline affinity by 15-fold .
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Osmoprotection Hierarchy: OpuB is prioritized under sulfur-limiting conditions due to choline-O-sulfate uptake via OpuC .
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Genetic Redundancy: opuBD deletion strains retain partial choline uptake via OpuC, highlighting functional overlap .
Applications in Research
Recombinant OpuBD is primarily used for:
Product Specs
Note: We will prioritize shipping the format currently in stock. However, if you have a specific format requirement, please indicate it in your order. We will prepare the product according to your request.
Note: All proteins are shipped with standard blue ice packs. If you require dry ice shipping, please notify us in advance. Additional fees will apply.
The tag type will be determined during the production process. If you have a specific tag type requirement, please communicate with us. We will prioritize development of the specified tag.
Target Background
KEGG: bsu:BSU33700
STRING: 224308.Bsubs1_010100018286
