5KU5

Crystal Structure of CusS Sensor Domain with Silver Bound

5KU5 の概要

• エントリーDOI: 10.2210/pdb5ku5/pdb
• 分子名称: Sensor kinase CusS, SILVER ION, ACETATE ION, ... (4 entities in total)
• 機能のキーワード: pdc fold, histidine kinase, silver binding, metal efflux system, transferase
• 由来する生物種: Escherichia coli (strain K12)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 68402.84

構造登録者

Affandi, T.,Issaian, A.V.,McEvoy, M.M. (登録日: 2016-07-12, 公開日: 2016-09-14, 最終更新日: 2024-03-06)

主引用文献

Affandi, T.,Issaian, A.V.,McEvoy, M.M.
The Structure of the Periplasmic Sensor Domain of the Histidine Kinase CusS Shows Unusual Metal Ion Coordination at the Dimeric Interface.
Biochemistry, 55:5296-5306, 2016

PubMed Abstract: In bacteria, two-component systems act as signaling systems to respond to environmental stimuli. Two-component systems generally consist of a sensor histidine kinase and a response regulator, which work together through histidyl-aspartyl phosphorelay to result in gene regulation. One of the two-component systems in Escherichia coli, CusS-CusR, is known to induce expression of cusCFBA genes at increased periplasmic Cu(I) and Ag(I) concentrations to help maintain metal ion homeostasis. CusS is a membrane-associated histidine kinase with a periplasmic sensor domain connected to the cytoplasmic ATP binding and catalytic domains through two transmembrane helices. The mechanism of how CusS senses increasing metal ion concentrations and activates CusR is not yet known. Here, we present the crystal structure of the Ag(I)-bound periplasmic sensor domain of CusS at a resolution of 2.15 Å. The structure reveals that CusS forms a homodimer with four Ag(I) binding sites per dimeric complex. Two symmetric metal binding sites are found at the dimeric interface, which are each formed by two histidines and one phenylalanine with an unusual cation-π interaction. The other metal ion binding sites are in a nonconserved region within each monomer. Functional analyses of CusS variants with mutations in the metal sites suggest that the metal ion binding site at the dimer interface is more important for function. The structural and functional data provide support for a model in which metal-induced dimerization results in increases in kinase activity in the cytoplasmic domains of CusS.

PubMed: 27583660
DOI: 10.1021/acs.biochem.6b00707

実験手法

X-RAY DIFFRACTION (2.15 Å)