5NC8

Shewanella denitrificans Kef CTD in AMP bound form

Summary for 5NC8

• Entry DOI: 10.2210/pdb5nc8/pdb
• Descriptor: Potassium efflux system protein, ADENOSINE MONOPHOSPHATE (2 entities in total)
• Functional Keywords: ktn/rck domain, kef, amp, potassium efflux, transport protein
• Biological source: Shewanella denitrificans OS217
• Total number of polymer chains: 2
• Total formula weight: 53584.00

Authors

Pliotas, C.,Naismith, J.H. (deposition date: 2017-03-03, release date: 2017-04-12, Last modification date: 2024-01-17)

Primary citation

Pliotas, C.,Grayer, S.C.,Ekkerman, S.,Chan, A.K.N.,Healy, J.,Marius, P.,Bartlett, W.,Khan, A.,Cortopassi, W.A.,Chandler, S.A.,Rasmussen, T.,Benesch, J.L.P.,Paton, R.S.,Claridge, T.D.W.,Miller, S.,Booth, I.R.,Naismith, J.H.,Conway, S.J.
Adenosine Monophosphate Binding Stabilizes the KTN Domain of the Shewanella denitrificans Kef Potassium Efflux System.
Biochemistry, 56:4219-4234, 2017

PubMed Abstract: Ligand binding is one of the most fundamental properties of proteins. Ligand functions fall into three basic types: substrates, regulatory molecules, and cofactors essential to protein stability, reactivity, or enzyme-substrate complex formation. The regulation of potassium ion movement in bacteria is predominantly under the control of regulatory ligands that gate the relevant channels and transporters, which possess subunits or domains that contain Rossmann folds (RFs). Here we demonstrate that adenosine monophosphate (AMP) is bound to both RFs of the dimeric bacterial Kef potassium efflux system (Kef), where it plays a structural role. We conclude that AMP binds with high affinity, ensuring that the site is fully occupied at all times in the cell. Loss of the ability to bind AMP, we demonstrate, causes protein, and likely dimer, instability and consequent loss of function. Kef system function is regulated via the reversible binding of comparatively low-affinity glutathione-based ligands at the interface between the dimer subunits. We propose this interfacial binding site is itself stabilized, at least in part, by AMP binding.

PubMed: 28656748
DOI: 10.1021/acs.biochem.7b00300

Experimental method

X-RAY DIFFRACTION (3.09 Å)