The Chromobacterium violaceum ArsR Arsenite Repressor Exerts Tighter Control on Its Cognate Promoter Than the Escherichia coil System

Autor(es)

Arruda, Leticia M. ; Monteiro, Lummy M. O. ; Silva-Rocha, Rafael

• Tipo de documento: Artigo Científico
• Fonte: FRONTIERS IN MICROBIOLOGY; v. 7, NOV 21 2016.
• Citações Web of Science: 2

Resumo

Environmental bacteria are endowed with several regulatory systems that have potential applications in biotechnology. In this report, we characterize the arsenic biosensing features of the ars response system from Chromobacterium violaceum in the heterologous host Escherichia coli. We show that the native Pars/arsR system of C. violaceum outperforms the chromosomal ars copy of E. coil when exposed to micromolar concentrations of arsenite. To understand the molecular basis of this phenomenon, we analyzed the interaction between ArsR regulators and their promoter target sites as well as induction of the system at saturating concentrations of the regulators. in vivo titration experiments indicate that ArsR from C. violaceum has stronger binding affinity for its target promoter than the regulator from E coil does. Additionally, arsenite induction experiments at saturating regulator concentration demonstrates that although the Pars/arsR system from E. coli displays a gradual response to increasing concentration of the inducer, the system from C. violaceum has a steeper response with a stronger promoter induction after a given arsenite threshold. Taken together, these data demonstrate the characterization of a novel arsenic response element from an environmental bacterium with potentially enhanced performance that could be further explored for the construction of an arsenic biosensor. (AU)

• Processo FAPESP: 12/22921-8 - Abordagens de biologia sintética para decifrar os mecanismos de integração de sinais em promotores bacterianos complexos
• Beneficiário: Rafael Silva Rocha
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 15/12553-0 - Construção de linhagens hospedeiras de E. coli para a caracterização de bibliotecas de promotores
• Beneficiário: Letícia Magalhães Arruda
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico