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The P seudomonas putida HskA hybrid sensor kinase controls the composition of the electron transport chain
Author(s) -
Sevilla Emma,
SilvaJiménez Hortencia,
Duque Estrella,
Krell Tino,
Rojo Fernando
Publication year - 2013
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12017
Subject(s) - autophosphorylation , kinase , biochemistry , protein kinase domain , phosphorylation , histidine kinase , gene , chemistry , microbiology and biotechnology , biology , protein kinase a , mutant
Summary Sensor kinases play a key role in sensing and responding to environmental and physiological signals in bacteria. In this study we characterized a previously unknown orphan hybrid sensor kinase from P seudomonas putida , which is conserved in several Pseudomonads. Inactivation of the gene coding for this sensor kinase, which we have named HskA , modified the expression of at least 85 genes in cells growing in a complete medium. HskA showed a strong influence on the composition of the electron transport chain. In cells growing exponentially in a complete medium, the absence of HskA led to a significant reduction in the expression of the genes coding for the bc1 complex and for the CIO and Cbb3‐1 terminal oxidases. In stationary phase cells, however, lack of HskA caused a higher expression of the Cyo terminal oxidase and a lower expression of the Aa3 terminal oxidase. The HskA polypeptide shows two PAS (signal‐sensing) domains, a transmitter domain containing the invariant phosphorylatable histidine and an ATP binding site, and a receiver domain containing the conserved aspartate capable of transphosphorylation, but lacks an Hpt module. It is therefore a hybrid sensor kinase. Phosphorylation assays showed that purified HskA undergoes autophosphorylation in the presence of ATP .