RESUMO
Archaea are motile by the rotation of the archaellum. The archaellum switches between clockwise and counterclockwise rotation, and movement along a chemical gradient is possible by modulation of the switching frequency. This modulation involves the response regulator CheY and the archaellum adaptor protein CheF. In this study, two new crystal forms and protein structures of CheY are reported. In both crystal forms, CheY is arranged in a domain-swapped conformation. CheF, the protein bridging the chemotaxis signal transduction system and the motility apparatus, was recombinantly expressed, purified and subjected to X-ray data collection.
Assuntos
Proteínas Arqueais/química , Proteínas Quimiotáticas Aceptoras de Metil/química , Pyrococcus horikoshii/química , Archaea/química , Archaea/genética , Archaea/metabolismo , Quimiotaxia/genética , Cristalografia por Raios X , Escherichia coli/metabolismo , Proteínas de Escherichia coli , Flagelos/metabolismo , Proteínas Quimiotáticas Aceptoras de Metil/biossíntese , Proteínas Quimiotáticas Aceptoras de Metil/genética , Conformação Proteica , Multimerização Proteica , Pyrococcus horikoshii/genética , Pyrococcus horikoshii/metabolismo , Transdução de SinaisRESUMO
In the process of optimization of heterologous expression of thermostable chemotaxis proteins CheW and CheY as industrially useful polypeptides, their direct influence on the cell growth kinetics and morphology of Escherichia coli was observed. CheW and CheY of bacteria of the genus Thermotoga, being expressed in recombinant form in E. coli cells, are involved in the corresponding signal pathways of the mesophilic microorganisms. The effects of such involvement in the metabolism of "host" cells are extremely diverse: from rapid aging of the culture to elongation of the stationary growth phase. We also discuss the mechanisms of the influence of the heterologous chemotaxis proteins on cells, their positive and negative effects, as well as potential applications in industry and biomedicine.