EC Number   |
Protein Variants |
Reference |
|---|
   7.6.2.9 | D149A |
decrease in choline binding affinity by approximately 18fold |
-, 720258 |
| 7.6.2.9 | D149A/L155A |
decrease in choline binding affinity by approximately 38fold |
720258 |
| 7.6.2.9 | D74A |
mutant is unable to bind choline |
-, 720258 |
| 7.6.2.9 | E171Q |
the monomer is the preferred species for the nucleotide-free state in solution |
656531 |
| 7.6.2.9 | F19W |
mutant analyzed |
685001 |
| 7.6.2.9 | G161C |
single cysteine mutants generated by site-directed mutagenesis |
685001 |
| 7.6.2.9 | L155A |
decrease in choline binding affinity by approximately 25fold |
-, 720258 |
| 7.6.2.9 | M21A |
decrease in choline binding affinity by approximately 3fold |
720258 |
| 7.6.2.9 | more |
construction of hybrids between the two ABC-transporters OpuB and OpuC from Bacillus subtilis by reciprocally exchanging the coding regions for the OpuBC and OpuCC substrate-binding proteins between the corresponding opuB and opuC operons resulting in strains TMB118 and LTB1. Exchanging the binding protein between the two ABC transporters inverses the substrate specificity, OpuB::OpuCC turns into a promiscuous system, while OpuC::OpuBC now exhibits narrow substrate specificity, each in contrast to the wild-type. Both hybrid transporters possess a high affinity for their substrates but the transport capacity of the OpuB::OpuCC system is moderate due to the synthesis of only low amounts of the xenogenetic OpuCC protein. Suppressor mutations causing single amino acid substitutions in the GbsR repressor controlling the choline to glycine betaine biosynthesis pathway greatly improve OpuB::OpuCC-mediated compatible solute import through transcriptional up-regulation of the hybrid opuB::opuCC operon. OpuB transporter lacking its solute receptor protein OpuBC is nonfunctional, which is also true for OpuC. The hybrid OpuB::OpuCC transporter is inefficient to relieve osmotic stress. De-repression of transcription of the opuB::opuCC operon is responsible for enhanced growth of the suppressor mutants at high salinity |
-, 751583 |
| 7.6.2.9 | more |
construction of hybrids between the two ABC-transporters OpuB and OpuC from Bacillus subtilis by reciprocally exchanging the coding regions for the OpuBC and OpuCC substrate-binding proteins between the corresponding opuB and opuC operons resulting in strains TMB118 and LTB1. Exchanging the binding protein between the two ABC transporters inverses the substrate specificity, OpuB::OpuCC turns into a promiscuous system, while OpuC::OpuBC now exhibits narrow substrate specificity, each in contrast to the wild-type. Both hybrid transporters possess a high affinity for their substrates but the transport capacity of the OpuB::OpuCC system is moderate due to the synthesis of only low amounts of the xenogenetic OpuCC protein. Suppressor mutations causing single amino acid substitutions in the GbsR repressor controlling the choline to glycine betaine biosynthesis pathway greatly improve OpuB::OpuCC-mediated compatible solute import through transcriptional up-regulation of the hybrid opuB::opuCC operon. OpuC transporter lacking its solute receptor protein OpuBC is nonfunctional, which is also true for OpuB |
-, 751583 |
