Riboflavin Transporter Ribu (Ribu) (LLNZ_06150) Lactococcus Lactis Subsp. Cremoris Recombinant Protein

Function: Probably a riboflavin-binding protein that interacts with the energy-coupling factor (ECF) ABC-transporter complex. Unlike classic ABC transporters this ECF transporter provides the energy necessary to transport a number of different substrates. The substrates themselves are bound by transmembrane, not extracytoplasmic soluble proteins

By similarity. Mediates riboflavin uptake, probably also transports FMN and roseoflavin. Ref.1

Enzyme regulation: Inhibited by FMN and roseoflavin. Ref.1

Subunit structure: Forms a stable energy-coupling factor (ECF) transporter complex composed of a membrane-embedded substrate-binding protein (S component), two ATP-binding proteins (A and A' components) and a transmembrane protein (T component)

By similarity.

Subcellular location: Cell membrane; Multi-pass membrane protein Ref.3.

Induction: Induced by riboflavin deficiency. Ref.1

Domain: Riboflavin is stacked with one or more Trp residues in the binding pocket of RibU. Ref.3

Disruption phenotype: Mutant exhibits altered transcriptional control of the riboflavin biosynthesis operon in response to riboflavin and FMN, and does not consume riboflavin from the growth medium. Ref.1

Miscellaneous: Riboflavin, FMN and roseoflavin, but not FAD, bind to RibU with high affinity and 1:1 stoichiometry.

Sequence similarities: Belongs to the prokaryotic riboflavin transporter (P-RFT) (TC 2.A.87) family. [View classification]