PDBsum entry 4zs9

Transport protein

PDB id: 4zs9

Contents

Protein chains

377 a.a.

Ligands

FRU-GLC-GLA ×2

Metals

_CL ×4

_MG ×15

Waters ×1114

PDB id:

4zs9

Name:

Transport protein

Title:

Raffinose and panose binding protein from bifidobacterium animalis subsp. Lactis bl-04, bound with raffinose

Structure:

Sugar binding protein of abc transporter system. Chain: a, b. Engineered: yes

Source:

Bifidobacterium animalis subsp. Lactis bl-04. Organism_taxid: 580050. Gene: balac_1599. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008. Expression_system_variant: de3

Resolution:

1.37Å R-factor: 0.134 R-free: 0.167

Authors:

F.Fredslund,M.Ejby,J.M.Andersen,D.J.Slotboom,M.Abou Hachem

Key ref:

M.Ejby et al. (2016). An ATP Binding Cassette Transporter Mediates the Uptake of α-(1,6)-Linked Dietary Oligosaccharides in Bifidobacterium and Correlates with Competitive Growth on These Substrates. J Biol Chem, 291, 20220-20231. PubMed id: 27502277

Date:

13-May-15 Release date: 29-Jun-16

Protein chains

A0A1A9TA69  (A0A1A9TA69_BIFLB) -  Sugar binding protein of ABC transporter system from Bifidobacterium animalis subsp. lactis (strain Bl-04 / DGCC2908 / RB 4825 / SD5219)

Seq: 393 a.a.

Struc: 377 a.a.

J Biol Chem 291:20220-20231 (2016)

PubMed id: 27502277

An ATP Binding Cassette Transporter Mediates the Uptake of α-(1,6)-Linked Dietary Oligosaccharides in Bifidobacterium and Correlates with Competitive Growth on These Substrates.

M.Ejby, F.Fredslund, J.M.Andersen, A.Vujičić Žagar, J.R.Henriksen, T.L.Andersen, B.Svensson, D.J.Slotboom, M.Abou Hachem.

ABSTRACT

The molecular details and impact of oligosaccharide uptake by distinct human gut microbiota (HGM) are currently not well understood. Non-digestible dietary galacto- and gluco-α-(1,6)-oligosaccharides from legumes and starch, respectively, are preferentially fermented by mainly bifidobacteria and lactobacilli in the human gut. Here we show that the solute binding protein (BlG16BP) associated with an ATP binding cassette (ABC) transporter from the probiotic Bifidobacterium animalis subsp. lactis Bl-04 binds α-(1,6)-linked glucosides and galactosides of varying size, linkage, and monosaccharide composition with preference for the trisaccharides raffinose and panose. This preference is also reflected in the α-(1,6)-galactoside uptake profile of the bacterium. Structures of BlG16BP in complex with raffinose and panose revealed the basis for the remarkable ligand binding plasticity of BlG16BP, which recognizes the non-reducing α-(1,6)-diglycoside in its ligands. BlG16BP homologues occur predominantly in bifidobacteria and a few Firmicutes but lack in other HGMs. Among seven bifidobacterial taxa, only those possessing this transporter displayed growth on α-(1,6)-glycosides. Competition assays revealed that the dominant HGM commensal Bacteroides ovatus was out-competed by B. animalis subsp. lactis Bl-04 in mixed cultures growing on raffinose, the preferred ligand for the BlG16BP. By comparison, B. ovatus mono-cultures grew very efficiently on this trisaccharide. These findings suggest that the ABC-mediated uptake of raffinose provides an important competitive advantage, particularly against dominant Bacteroides that lack glycan-specific ABC-transporters. This novel insight highlights the role of glycan transport in defining the metabolic specialization of gut bacteria.