EC Number   |
General Information |
Reference |
|---|
   7.6.2.8 | physiological function |
the ABC transporter BtuCD-F imports vitamin B12 across the inner membrane of Escherichia coli. Substrate translocation by ATP-binding cassette (ABC) transporters involves coupling of ATP binding and hydrolysis in the nucleotide-binding domains (NBDs) to conformational changes in the transmembrane domains |
750063 |
| 7.6.2.8 | physiological function |
the ATP-binding cassette (ABC) importer family catalyzse the uptake of nutrients, vitamins and trace elements. Membrane transport proteins generally are inherently flexible and undergo substantial conformational changes to catalyze the translocation of their substrates across biological membranes. The vitamin B12 import system BtuCD-F from Escherichia coli shows the conformational dynamics during the transport cycle |
751644 |
| 7.6.2.8 | physiological function |
the enzyme is required for the assimilation of exogenous vitamin B12 to enable methylmalonyl-CoA pathway function and is essential for corrinoid transport |
734820 |
| 7.6.2.8 | physiological function |
the membrane protein BtuM acts as transporter for uptake of essential vitamin B12, i.e. cobalamin, one of the most complex cofactors known, and used by enzymes catalyzing for instance methyl-group transfer and ribonucleotide reduction reactions. BtuMTd likely combines two functions: transport of the substrate into the bacterial cell, and chemical modification of the substrate. A cobalt-cysteine interaction allows for chemical modification of the substrate prior to translocation, which is a rare feature among uptake systems. BtuM homologues are small membrane proteins of about 22 kDa, and found predominantly in Gram-negative species, distributed mostly over alpha-, beta-, and gamma-proteobacteria |
751670 |
| 7.6.2.8 | physiological function |
vitamin B12 importer BtuCD is a type II ATP binding cassette (ABC) importer mediating the uptake of vitamin B12 across the inner membrane. ABC transporters utilize the energy of ATP hydrolysis to unidirectionally transport substrates across cell membrane. ATP hydrolysis occurs at the nucleotide-binding domain (NBD) dimer interface of ABC transporters, whereas substrate translocation takes place at the translocation pathway between the transmembrane domains (TMDs), which is more than 30 A away from the NBD dimer interface |
751956 |
