title: Enterococcus faecalis zinc-responsive proteins mediate bacterial defence against zinc overload, lysozyme and oxidative stress.
abstract: Two Enterococcus faecalis genes encoding the P-type ATPase EF1400 and the putative SapB protein EF0759 were previously shown to be strongly upregulated in the presence of high concentrations of zinc. In the present work, we showed that a Zn(2+)-responsive DNA-binding motif (zim) is present in the promoter regions of these genes. Both proteins were further studied with respect to their involvement in zinc homeostasis and invasion of the host. EF0759 contributed to intramacrophage survival by an as-yet unknown mechanism(s). EF1400, here renamed ZntAEf, is an ATPase with specificity for zinc and plays a role in dealing with several host defences, i.e. zinc overload, oxidative stress and lysozyme; it provides E. faecalis cells with the ability to survive inside macrophages. As these three host defence mechanisms are important at several sites in the host, i.e. inside macrophages and in saliva, this work suggested that ZntAEf constitutes a crucial E. faecalis defence mechanism that is likely to contribute to the ability of this bacterium to endure life inside its host.
authors.affiliation: Department of Molecular Genetics, University of Groningen, The Netherlands.|Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República, 2780-157 Oeiras, Portugal.
authors.forename: Marta C
authors.initials: MC
authors.lastname: Abrantes
authors.affiliation: Department of Molecular Genetics, University of Groningen, The Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Kok
authors.affiliation: IBET, Apartado 12, 2781-901 Oeiras, Portugal.|Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República, 2780-157 Oeiras, Portugal.
authors.forename: Maria de Fátima
authors.initials: MF
authors.lastname: Silva Lopes
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D050296:Microbial Viability / Q000187:drug effects; D009113:Muramidase / Q000378:metabolism*; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D013312:Stress, Physiological; D015032:Zinc / Q000378:metabolism* / Q000633:toxicity
chemical_list: D001426:Bacterial Proteins; D009113:Muramidase; D015032:Zinc