MECHANISM OF IRON STORAGE BY BLOOM-FORMING PENNATE DIATOMS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 铁蛋白是一个广泛的铁储存和解毒蛋白超家族，存在于植物、哺乳动物和许多微生物中。在海洋羽状硅藻中发现了一种新的铁蛋白，这种单细胞光合作用生物在全球初级生产和深海固碳方面发挥着重要作用。从羽状硅藻伪菱形藻多系列(PmFTN)中提取的铁蛋白的晶体结构揭示了铁蛋白铁氧基酶中心、单体折叠和球形组装的特征。从铁(II)和锌(II)的晶体浸泡实验和反常分散数据中确定了三个金属位(A，B，C)。观察到的铁和锌原子形成了一条通向中央空腔的路径，在那里形成了储存的铁矿物。金属配位残基被认为是为了阻止铁从铁氧基酶位置进入矿核。我们将测定金属配位氨基酸在铁(II)存在下的各种变体的晶体结构，并进一步了解PmFTN的储铁机制。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Ferritins are a broad superfamily of iron storage and detoxifying proteins found in plants, mammals and many microorganisms. A novel ferritin was found in marine pennate diatoms, unicellular photosynthetic organisms that play a major role in global primary production and carbon sequestration in the deep ocean. Crystal structures of ferritin derived from the pennate diatom Pseudo-nitzschia multiseries (PmFTN) revealed the characteristic ferritin ferroxidase centres, monomeric fold and spherical assembly. Three metal sites (A, B, C) were identified from iron(II) and zinc(II) crystal soaking experiments and anomalous dispersion data. The observed iron and zinc atoms form a pathway leading towards the central cavity where the stored iron mineral is formed. Metal coordinating residues are hypothesized to gate the passage of iron from the ferroxidase site to nucleate the mineral core. We will determine crystal structures of variants of metal coordinating amino acids in the presence of iron(II) and to gain further insights into the iron storage mechanism of PmFTN.