کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2184827 1095935 2013 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Helix Bundle Loops Determine Whether Histidine Kinases Autophosphorylate in cis or in trans
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Helix Bundle Loops Determine Whether Histidine Kinases Autophosphorylate in cis or in trans
چکیده انگلیسی

Bacteria frequently use two-component signal transduction pathways to sense and respond to environmental and intracellular stimuli. Upon receipt of a stimulus, a homodimeric sensor histidine kinase autophosphorylates and then transfers its phosphoryl group to a cognate response regulator. The autophosphorylation of histidine kinases has been reported to occur both in cis and in trans, but the molecular determinants dictating which mechanism is employed are unknown. Based on structural considerations, one model posits that the handedness of a loop at the base of the helical dimerization domain plays a critical role. Here, we tested this model by replacing the loop from Escherichia coli EnvZ, which autophosphorylates in trans, with the loop from three PhoR orthologs that autophosphorylate in cis. These chimeric kinases autophosphorylated in cis, indicating that this small loop is sufficient to determine autophosphorylation mechanism. Further, we report that the mechanism of autophosphorylation is conserved in orthologous sets of histidine kinases despite highly dissimilar loop sequences. These findings suggest that histidine kinases are under selective pressure to maintain their mode of autophosphorylation, but they can do so with a wide range of sequences.

Graphical AbstractFigure optionsDownload high-quality image (125 K)Download as PowerPoint slideHighlights
► Dimeric histidine kinases autophosphorylate either in cis or in trans.
► Autophosphorylation mechanism (cis or trans) is conserved among orthologous kinases.
► Swapping a single loop can switch the kinase EnvZ from a cis to trans mechanism.
► The helix bundle loop in histidine kinases dictates autophosphorylation mechanism.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Biology - Volume 425, Issue 7, 12 April 2013, Pages 1198–1209
نویسندگان
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