PDBsum entry 6ytc

Protein transport

PDB id: 6ytc

Contents

Protein chain

93 a.a.

PDB id:

6ytc

Name:

Protein transport

Title:

Solution nmr structure of the isolated nte domain of bt1762-63 levan transporter

Structure:

Tonb-dependent receptor. Chain: a. Engineered: yes

Source:

Bacteroides thetaiotaomicron. Organism_taxid: 818. Gene: hmpref2534_01945. Expressed in: escherichia coli. Expression_system_taxid: 562

NMR struc:

20 models

Authors:

P.Rath,A.Mazur,S.Hiller

Key ref:

D.A.Gray et al. (2021). Insights into SusCD-mediated glycan import by a prominent gut symbiont. Nat Commun, 12, 44. PubMed id: 33398001 DOI: 10.1038/s41467-020-20285-y

Date:

24-Apr-20 Release date: 08-Jul-20

Protein chain

Q8A6W3  (Q8A6W3_BACTN) -  SusC homolog from Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / JCM 5827 / CCUG 10774 / NCTC 10582 / VPI-5482 / E50)

Seq: 1041 a.a.

Struc: 93 a.a.*

* PDB and UniProt seqs differ at 9 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1038/s41467-020-20285-y

Nat Commun 12:44 (2021)

PubMed id: 33398001

Insights into SusCD-mediated glycan import by a prominent gut symbiont.

D.A.Gray, J.B.R.White, A.O.Oluwole, P.Rath, A.J.Glenwright, A.Mazur, M.Zahn, A.Baslé, C.Morland, S.L.Evans, A.Cartmell, C.V.Robinson, S.Hiller, N.A.Ranson, D.N.Bolam, B.van den Berg.

ABSTRACT

In Bacteroidetes, one of the dominant phyla of the mammalian gut, active uptake of large nutrients across the outer membrane is mediated by SusCD protein complexes via a "pedal bin" transport mechanism. However, many features of SusCD function in glycan uptake remain unclear, including ligand binding, the role of the SusD lid and the size limit for substrate transport. Here we characterise the β2,6 fructo-oligosaccharide (FOS) importing SusCD from Bacteroides thetaiotaomicron (Bt1762-Bt1763) to shed light on SusCD function. Co-crystal structures reveal residues involved in glycan recognition and suggest that the large binding cavity can accommodate several substrate molecules, each up to ~2.5 kDa in size, a finding supported by native mass spectrometry and isothermal titration calorimetry. Mutational studies in vivo provide functional insights into the key structural features of the SusCD apparatus and cryo-EM of the intact dimeric SusCD complex reveals several distinct states of the transporter, directly visualising the dynamics of the pedal bin transport mechanism.