5FIM: The structure of Kbp.K from E. coli

Escherichia coli possesses a number of specific K(+) influx and efflux systems that maintain an appropriate intracellular K(+) concentration. Although regulatory mechanisms have been identified for a number of these transport systems, the exact mechanism through which K(+) concentration is sensed in the cell remains unknown. In this work we show that Kbp (K(+) binding protein, formerly YgaU), a soluble 16-kDa cytoplasmic protein from Escherichia coli, is a highly specific K(+) binding protein and is required for normal growth in the presence of high levels of external K(+). Kbp binds a single potassium ion with high specificity over Na(+) and other metal ions found in biological systems, although, in common with K(+) transporters, it also binds Rb(+) and Cs(+). Dissection of the K(+) binding determinants of Kbp suggests a mechanism through which Kbp is able to sense changes in K(+) concentration over the relevant range of intracellular K(+) concentrations.
PDB ID: 5FIMDownload
MMDB ID: 138953
PDB Deposition Date: 2015/9/30
Updated in MMDB: 2018/05
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Biological Unit for 5FIM: monomeric; determined by author and by software (PQS)
Molecular Components in 5FIM
Label Count Molecule
Protein (1 molecule)
Ygau(Gene symbol: ygaU)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB