6FFL

Maltose/maltodextrin-binding domain MalE from Bdellovibrio bacteriovorus bound to maltotriose

Summary for 6FFL

• Entry DOI: 10.2210/pdb6ffl/pdb
• Related PRD ID: PRD_900009
• Descriptor: Maltose/maltodextrin transport permease homologue, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, PLATINUM (II) ION, ... (5 entities in total)
• Functional Keywords: carbohydrate binding protein, sugar binding protein
• Biological source: Bdellovibrio bacteriovorus HD100
• Total number of polymer chains: 1
• Total formula weight: 44956.14

Authors

Licht, A.,Werther, T.,Bommer, M.,Neumann, K.,Schneider, E. (deposition date: 2018-01-08, release date: 2018-01-24, Last modification date: 2024-05-08)

Primary citation

Licht, A.,Bommer, M.,Werther, T.,Neumann, K.,Hobe, C.,Schneider, E.
Structural and functional characterization of a maltose/maltodextrin ABC transporter comprising a single solute binding domain (MalE) fused to the transmembrane subunit MalF.
Res. Microbiol., 170:1-12, 2018

PubMed Abstract: Canonical ATP-binding cassette import systems rely on extracellular substrate binding proteins (SBP) for function. In gram-negative bacteria, SBPs are usually freely diffusible in the periplasm and, where studied, exist in excess over their cognate transporters. However, in vitro studies with the maltose transporter of Escherichia coli (MalFGK) have demonstrated that mechanistically one copy of its SBP (MalE) per transport complex is sufficient for activity. To address whether such a condition is physiologically relevant, we have characterized a homolog of the E. coli system from the gram-negative bacterium Bdellovibrio bacteriovorus which has a single copy of a maltose binding domain fused to the MalF subunit. Both transporters share substrate specificity for maltose and linear maltodextrins. Specific ATPase and transport activities of the B. bacteriovorus transporter were comparable to those of the E. coli system assayed at a 1:1 M ratio of MalE to the transport complex. While MalE was able to additionally increase ATPase activity of MalFGK, the isolated MalE domain of B. bacteriovorus failed to stimulate the E. coli system. Strikingly, interactions of the MalE domain with the transmembrane subunits during the transport cycle as studied by site-specific cross-linking were found to differ from those observed for E. coli MalE-FGK.

PubMed: 30193862
DOI: 10.1016/j.resmic.2018.08.006

Experimental method

X-RAY DIFFRACTION (1.707 Å)