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的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 羧基体是原始的细菌细胞器，其在无机碳受限的条件下作为碳浓缩机制（CCM）的一部分起作用。羧基体通过将碳酸酐酶和CO2固定酶核酮糖-1，5-二磷酸羧化酶/加氧酶（RuBisCO）包封在一起来增强细胞碳固定的效率。羧基体大致呈二十面体形状，外壳直径在800到1500之间，由几千个小的蛋白质亚基组成。在蓝细菌集胞藻PCC 6803中，先前对两个同源壳蛋白亚基CcmK 2和CcmK 4的结构测定阐明了外壳是如何通过CcmK六聚体紧密包装成分子层而形成的。本计画的目标是阐明形成羧基体的壳蛋白的结构。

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.