5MDR

Crystal structure of in vitro folded Chitoporin VhChip from Vibrio harveyi in complex with chitohexaose

Summary for 5MDR

• Entry DOI: 10.2210/pdb5mdr/pdb
• Descriptor: Chitoporin, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, (HYDROXYETHYLOXY)TRI(ETHYLOXY)OCTANE, ... (5 entities in total)
• Functional Keywords: outer membrane protein vibrio harveyi porin channel, sugar binding protein
• Biological source: Vibrio harveyi
• Total number of polymer chains: 6
• Total formula weight: 247590.60

Authors

Zahn, M.,van den Berg, B. (deposition date: 2016-11-13, release date: 2017-12-20, Last modification date: 2024-10-16)

Primary citation

Aunkham, A.,Zahn, M.,Kesireddy, A.,Pothula, K.R.,Schulte, A.,Basle, A.,Kleinekathofer, U.,Suginta, W.,van den Berg, B.
Structural basis for chitin acquisition by marine Vibrio species.
Nat Commun, 9:220-220, 2018

PubMed Abstract: Chitin, an insoluble polymer of N-acetylglucosamine, is one of the most abundant biopolymers on Earth. By degrading chitin, chitinolytic bacteria such as Vibrio harveyi are critical for chitin recycling and maintenance of carbon and nitrogen cycles in the world's oceans. A decisive step in chitin degradation is the uptake of chito-oligosaccharides by an outer membrane protein channel named chitoporin (ChiP). Here, we report X-ray crystal structures of ChiP from V. harveyi in the presence and absence of chito-oligosaccharides. Structures without bound sugar reveal a trimeric assembly with an unprecedented closing of the transport pore by the N-terminus of a neighboring subunit. Substrate binding ejects the pore plug to open the transport channel. Together with molecular dynamics simulations, electrophysiology and in vitro transport assays our data provide an explanation for the exceptional affinity of ChiP for chito-oligosaccharides and point to an important role of the N-terminal gate in substrate transport.

PubMed: 29335469
DOI: 10.1038/s41467-017-02523-y

Experimental method

X-RAY DIFFRACTION (1.9 Å)