Structure-function relationship of chimeric KdpFABC complex

Informazioni relative al progetto

KdpFABC

ID dell’accordo di sovvenzione: 749732

DOI

10.3030/749732

Progetto concluso il 31 Maggio 2018

Data della firma CE 17 Marzo 2017

Data di avvio 1 Agosto 2017

Data di completamento 31 Luglio 2019

Finanziato da

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Costo totale

€ 177 598,80

Contributo UE

€ 177 598,80

Coordinato da

RIJKSUNIVERSITEIT GRONINGEN
Netherlands

Periodic Reporting for period 1 - KdpFABC (Structure-function relationship of chimeric KdpFABC complex)

Periodo di rendicontazione: 2017-08-01 al 2019-07-31

Sintesi del contesto e degli obiettivi generali del progetto

The structure-function relationships that explain the transport mechanism of membrane proteins on a molecular level are poorly understood and define one of the most complex and interdisciplinary research fields at the interface of Biology, Chemistry and Physics. The main objective of this project was to investigate the KdpFABC complex, a survival potassium uptake in bacteria. It combines features of three membrane transport systems (P-type ATPases, channels and ABC transporters), which traditionally are considered to be mechanistically and structurally distinct. A central question was to decipher the mechanism of action of the KdpFABC system, which is likely to overthrow the conceptual boundaries conventionally used to describe membrane transport mechanisms. The results might lead to a broader understanding of transport mechanism and to the design of novel antibiotics, as these systems are exclusively found in prokaryotes.

Lavoro eseguito dall’inizio del progetto fino alla fine del periodo coperto dalla relazione e principali risultati finora ottenuti

During the period of the project we were able to obtain the structure of two distinct states of the protein complex by using the technique of high-resolution single particle cryo-electron microscopy. The new findings allowed to proposed a new mechanism of transport for the complex, which is so far unprecedented among other known mechanisms. Other than expected, not solely the channel-like subunit KdpA facilitates K+ translocation, but rather the combination of two joined half-channels formed by KdpA and KdpB, revealing a true chimera between a transporter and a channel. It demonstrates how in the course of evolution conserved protein architectures not only evolved from one another but can merge together to adapt to different environmental and cellular requirements.

Progressi oltre lo stato dell’arte e potenziale impatto previsto (incluso l’impatto socioeconomico e le implicazioni sociali più ampie del progetto fino ad ora)

Our results highlight a new mechanism of transport, which differs from what was postulated initially for this protein complex. We hope in the future to be able to describe the mechanism of action, the coupling between the subunits and the regulation of the complex in more detail. We aim to obtain further structures of the complex at different conformational states and contrast our findings to biochemical studies. Ultimately, we hope to encipher the equally simple and complex way by which membrane proteins complex operate. Our findings will not only have an impact on our general understanding of transport mechanism, but might provide the basis for the development of new bactericidal or bacteriostatic compounds.

New mechanism of transport in the KpdFABC complex