A mycobacterial ABC transporter mediates the uptake of hydrophilic compounds.
Nature
; 580(7803): 409-412, 2020 04.
Article
in En
| MEDLINE
| ID: mdl-32296172
ABSTRACT
Mycobacterium tuberculosis (Mtb) is an obligate human pathogen and the causative agent of tuberculosis1-3. Although Mtb can synthesize vitamin B12 (cobalamin) de novo, uptake of cobalamin has been linked to pathogenesis of tuberculosis2. Mtb does not encode any characterized cobalamin transporter4-6; however, the gene rv1819c was found to be essential for uptake of cobalamin1. This result is difficult to reconcile with the original annotation of Rv1819c as a protein implicated in the transport of antimicrobial peptides such as bleomycin7. In addition, uptake of cobalamin seems inconsistent with the amino acid sequence, which suggests that Rv1819c has a bacterial ATP-binding cassette (ABC)-exporter fold1. Here, we present structures of Rv1819c, which reveal that the protein indeed contains the ABC-exporter fold, as well as a large water-filled cavity of about 7,700 Å3, which enables the protein to transport the unrelated hydrophilic compounds bleomycin and cobalamin. On the basis of these structures, we propose that Rv1819c is a multi-solute transporter for hydrophilic molecules, analogous to the multidrug exporters of the ABC transporter family, which pump out structurally diverse hydrophobic compounds from cells8-11.
Full text:
1
Database:
MEDLINE
Main subject:
Bacterial Proteins
/
Bleomycin
/
ATP-Binding Cassette Transporters
/
Mycobacterium tuberculosis
Language:
En
Journal:
Nature
Year:
2020
Type:
Article
Affiliation country:
Netherlands