Instituto de Microbiologia Paulo de Góes, CCS, Bloco I, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil.
J Struct Biol. 2013 Feb;181(2):162-8. doi: 10.1016/j.jsb.2012.12.002. Epub 2012 Dec 12.
We examined the structure and biomineralization of prismatic magnetosomes in the magnetotactic marine vibrio Magnetovibrio blakemorei strain MV-1 and a non-magnetotactic mutant derived from it, using a combination of cryo-electron tomography and freeze-fracture. The vesicles enveloping the Magnetovibrio magnetosomes were elongated and detached from the cell membrane. Magnetosome crystal formation appeared to be initiated at a nucleation site on the membrane inner surface. Interestingly, while scattered filaments were observed in the surrounding cytoplasm, their association with the magnetosome chains could not be unequivocally established. Our data suggest fundamental differences between prismatic and octahedral magnetosomes in their mechanisms of nucleation and crystal growth as well as in their structural relationships with the cytoplasm and plasma membrane.
我们使用冷冻电子断层扫描和冷冻断裂技术，研究了海洋趋磁细菌 Magnetovibrio blakemorei 菌株 MV-1 及其衍生的非趋磁突变体中棱柱形磁小体的结构和生物矿化。包围 Magnetovibrio 磁小体的小泡呈长形且与细胞膜分离。磁小体晶体的形成似乎是在膜内表面的成核部位开始的。有趣的是，虽然在周围细胞质中观察到分散的细丝，但它们与磁小体链的关联尚不能明确确定。我们的数据表明，棱柱形和八面体磁小体在成核和晶体生长机制以及与细胞质和质膜的结构关系方面存在根本差异。
