STRUCTURES OF THE SHELL PROTEINS FROM THE ?-CARBOXYSOME (CCMK1 AND CCMK2)

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 羧基体是原始的细菌细胞器，在无机碳有限的条件下，它们作为碳浓缩机制(CCM)的一部分发挥作用。该羧体通过包裹碳酸酐酶和二氧化碳固定酶核酮糖-1，5-二磷酸羧基酶/加氧酶(Rubisco)来提高细胞的碳固定效率。羧体具有大致二十面体的形状，外壳直径在800到1500？之间，由几千个小的蛋白质亚基组成。在蓝藻聚胞藻中发现。PCC 6803，先前对CcmK2和CcmK4两个同源外壳蛋白亚基的结构测定，阐明了外壳是如何通过CcmK六聚体紧密堆积成分子层而形成的。这个项目的目标是阐明形成羧体的壳蛋白的结构。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Carboxysomes are primitive bacterial organelles that function as a part of a carbon concentrating mechanism (CCM) under conditions where inorganic carbon is limiting. The carboxysome enhances the efficiency of cellular carbon fixation by encapsulating together carbonic anhydrase and the CO2 fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). The carboxysome has a roughly icosahedral shape with an outer shell between 800 and1500 ¿ in diameter, which is constructed from a few thousand small protein subunits. In the cyanobacterium Synechocystis sp. PCC 6803, the previous structure determination of two homologous shell protein subunits, CcmK2 and CcmK4, elucidated how the outer shell is formed by the tight packing of CcmK hexamers into a molecular layer. The goal of this project is to elucidate the structures of the shell proteins forming the carboxysome.