Common ancestry of iron oxide- and iron-sulfide-based biomineralization in magnetotactic bacteria |
| |
Authors: | Fernanda Abreu Mauricio E Cant?o Marisa F Nicolás Fernando G Barcellos Viviana Morillo Luiz GP Almeida Fabrícia F do Nascimento Christopher T Lefèvre Dennis A Bazylinski Ana Tereza R de Vasconcelos Ulysses Lins |
| |
Institution: | 1.Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil;2.Laboratório de Bioinformática, Laboratório Nacional de Computação Científica, Rio de Janeiro, Brasil;3.Instituto Nacional de Metrologia, Normalização e Qualidade Industrial, Rio de Janeiro, Brasil;4.School of Life Sciences, University of Nevada at Las Vegas, Las Vegas, NV, USA |
| |
Abstract: | Magnetosomes are prokaryotic organelles produced by magnetotactic bacteria that consist of nanometer-sized magnetite (Fe3O4) or/and greigite (Fe3S4) magnetic crystals enveloped by a lipid bilayer membrane. In magnetite-producing magnetotactic bacteria, proteins present in the magnetosome membrane modulate biomineralization of the magnetite crystal. In these microorganisms, genes that encode for magnetosome membrane proteins as well as genes involved in the construction of the magnetite magnetosome chain, the mam and mms genes, are organized within a genomic island. However, partially because there are presently no greigite-producing magnetotactic bacteria in pure culture, little is known regarding the greigite biomineralization process in these organisms including whether similar genes are involved in the process. Here using culture-independent techniques, we now show that mam genes involved in the production of magnetite magnetosomes are also present in greigite-producing magnetotactic bacteria. This finding suggest that the biomineralization of magnetite and greigite did not have evolve independently (that is, magnetotaxis is polyphyletic) as once suggested. Instead, results presented here are consistent with a model in which the ability to biomineralize magnetosomes and the possession of the mam genes was acquired by bacteria from a common ancestor, that is, the magnetotactic trait is monophyletic. |
| |
Keywords: | biomineralization evolution greigite magnetite magnetotactic bacteria magnetosome horizontal gene transfer |
|
|