PDBsum entry 5aw2

Hydrolase/transport protein

PDB id: 5aw2

Contents

Protein chains

992 a.a.

268 a.a.

39 a.a.

Ligands

NAG-NAG

MF4

CLR

NAG

Metals

_TL ×3

_MG

__K

Waters ×1

PDB id:

5aw2

Name:

Hydrolase/transport protein

Title:

Kinetics by x-ray crystallography: tl+-substitution of bound k+ in the e2.Mgf42-.2k+ crystal after 85 min

Structure:

Na, k-atpase alpha subunit. Chain: a. Na+,k+-atpase beta subunit. Chain: b. Synonym: sodium/potassium-transporting atpase subunit beta-1. Phospholemman-like protein. Chain: g

Source:

Squalus acanthias. Spiny dogfish. Organism_taxid: 7797. Organism_taxid: 7797

Resolution:

3.20Å R-factor: 0.284 R-free: 0.280

Authors:

H.Ogawa,F.Cornelius,A.Hirata,C.Toyoshima

Key ref:

H.Ogawa et al. (2015). Sequential substitution of K(+) bound to Na(+),K(+)-ATPase visualized by X-ray crystallography. Nat Commun, 6, 8004. PubMed id: 26258479 DOI: 10.1038/ncomms9004

Date:

01-Jul-15 Release date: 02-Sep-15

Protein chain

Q4H132  (Q4H132_SQUAC) -  Sodium/potassium-transporting ATPase subunit alpha from Squalus acanthias

Seq: 1028 a.a.

Struc: 992 a.a.

Protein chain

C4IX13  (C4IX13_SQUAC) -  Sodium/potassium-transporting ATPase subunit beta from Squalus acanthias

Seq: 305 a.a.

Struc: 268 a.a.

Protein chain

Q70Q12  (Q70Q12_SQUAC) -  FXYD domain-containing ion transport regulator from Squalus acanthias

Seq: 94 a.a.

Struc: 39 a.a.

DOI no: 10.1038/ncomms9004

Nat Commun 6:8004 (2015)

PubMed id: 26258479

Sequential substitution of K(+) bound to Na(+),K(+)-ATPase visualized by X-ray crystallography.

H.Ogawa, F.Cornelius, A.Hirata, C.Toyoshima.

ABSTRACT

Na(+),K(+)-ATPase transfers three Na(+) from the cytoplasm into the extracellular medium and two K(+) in the opposite direction per ATP hydrolysed. The binding and release of Na(+) and K(+) are all thought to occur sequentially. Here we demonstrate by X-ray crystallography of the ATPase in E2·MgF4(2-)·2K(+), a state analogous to E2·Pi·2K(+), combined with isotopic measurements, that the substitution of the two K(+) with congeners in the extracellular medium indeed occurs at different rates, substantially faster at site II. An analysis of thermal movements of protein atoms in the crystal shows that the M3-M4E helix pair opens and closes the ion pathway leading to the extracellular medium, allowing K(+) at site II to be substituted first. Taken together, these results indicate that site I K(+) is the first cation to bind to the empty cation-binding sites after releasing three Na(+).