4CZA

Structure of the sodium proton antiporter PaNhaP from Pyrococcus abyssii with bound thallium ion.

Summary for 4CZA

• Entry DOI: 10.2210/pdb4cza/pdb
• Related: 4CZ8 4CZ9 4CZB
• Descriptor: NA+/H+ ANTIPORTER, PUTATIVE, TRIS(HYDROXYETHYL)AMINOMETHANE, octyl beta-D-glucopyranoside, ... (7 entities in total)
• Functional Keywords: membrane protein, transporter, exchanger, cpa
• Biological source: PYROCOCCUS ABYSSI GE5
• Total number of polymer chains: 2
• Total formula weight: 95056.74

Authors

Woehlert, D.,Kuhlbrandt, W.,Yildiz, O. (deposition date: 2014-04-16, release date: 2014-12-17, Last modification date: 2023-12-20)

Primary citation

Wohlert, D.,Kuhlbrandt, W.,Yildiz, O.
Structure and substrate ion binding in the sodium/proton antiporter PaNhaP.
Elife, 3:e03579-e03579, 2014

PubMed Abstract: Sodium/proton antiporters maintain intracellular pH and sodium levels. Detailed structures of antiporters with bound substrate ions are essential for understanding how they work. We have resolved the substrate ion in the dimeric, electroneutral sodium/proton antiporter PaNhaP from Pyrococcus abyssi at 3.2 Å, and have determined its structure in two different conformations at pH 8 and pH 4. The ion is coordinated by three acidic sidechains, a water molecule, a serine and a main-chain carbonyl in the unwound stretch of trans-membrane helix 5 at the deepest point of a negatively charged cytoplasmic funnel. A second narrow polar channel may facilitate proton uptake from the cytoplasm. Transport activity of PaNhaP is cooperative at pH 6 but not at pH 5. Cooperativity is due to pH-dependent allosteric coupling of protomers through two histidines at the dimer interface. Combined with comprehensive transport studies, the structures of PaNhaP offer unique new insights into the transport mechanism of sodium/proton antiporters.

PubMed: 25426802
DOI: 10.7554/eLife.03579

Experimental method

X-RAY DIFFRACTION (3.2 Å)