Asymmetric Preorganization of Inverted Pair Residues in the Sodium-Calcium Exchanger

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F16%3A00466079" target="_blank" >RIV/61388971:_____/16:00466079 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1038/srep20753" target="_blank" >http://dx.doi.org/10.1038/srep20753</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/srep20753" target="_blank" >10.1038/srep20753</a>

Result language

angličtina

Original language name

Asymmetric Preorganization of Inverted Pair Residues in the Sodium-Calcium Exchanger

Original language description

In analogy with many other proteins, Na+/Ca2+ exchangers (NCX) adapt an inverted twofold symmetry of repeated structural elements, while exhibiting a functional asymmetry by stabilizing an outward-facing conformation. Here, structure-based mutant analyses of the Methanococcus jannaschii Na+/Ca2+ exchanger (NCX_Mj) were performed in conjunction with HDX-MS (hydrogen/deuterium exchange mass spectrometry) to identify the structure-dynamic determinants of functional asymmetry. HDX-MS identified hallmark differences in backbone dynamics at ion-coordinating residues of apo-NCX_Mj, whereas Na+ or Ca2+ binding to the respective sites induced relatively small, but specific, changes in backbone dynamics. Mutant analysis identified ion-coordinating residues affecting the catalytic capacity (kcat/Km), but not the stability of the outward-facing conformation. In contrast, distinct "noncatalytic" residues (adjacent to the ion-coordinating residues) control the stability of the outward-facing conformation, but not the catalytic capacity. The helix-breaking signature sequences (GTSLPE) on the alpha(1) and alpha(2) repeats (at the ion-binding core) differ in their folding/unfolding dynamics, while providing asymmetric contributions to transport activities. The present data strongly support the idea that asymmetric preorganization of the ligand-free ion-pocket predefines catalytic reorganization of ion-bound residues, where secondary interactions with adjacent residues couple the alternating access. These findings provide a structure-dynamic basis for ion-coupled alternating access in NCX and similar proteins.

Czech name

—

Czech description

—

Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

CE - Biochemistry

OECD FORD branch

—

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Scientific Reports

ISSN

2045-2322

e-ISSN

—

Volume of the periodical

6

Issue of the periodical within the volume

FEB15

Country of publishing house

GB - UNITED KINGDOM

Number of pages

13

Pages from-to

—

UT code for WoS article

000370035500001

EID of the result in the Scopus database

2-s2.0-84958259365