NUCLEOTIDE TRANSPORTATION BY A MITOCHONDRIAL CARRIER

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。 三磷酸腺苷（ATP）的水解为细胞中的许多代谢反应提供能量。 在真核细胞中，ATP在线粒体内由腺苷二磷酸（ADP）和无机磷酸合成。 然后，新合成的ATP被输出到细胞质中消耗，而胞质ADP被输入到线粒体中进行ATP再生。 ADP和ATP跨线粒体膜的交换由线粒体ADP/ATP载体介导，线粒体ADP/ATP载体是一种膜蛋白，已提出其在两种构象上不同的状态（cytosolic-open（c-状态）和matrix-open（m-状态））之间循环，从而使核苷酸穿梭于线粒体内膜（http：//www.ks.uiuc.edu/Research/AdpAtpCarrier/）。 载体的C态是唯一已知的结构状态[1]。 因此，参与交换循环的载体的构象变化仍然难以捉摸。

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. The hydrolysis of adenosine triphosphate (ATP) provides energy for numerous metabolic reactions in a cell. In eukaryotic cells, ATP is synthesized inside the mitochondria from adenosine diphosphate (ADP) and inorganic phosphate. The newly synthesized ATP is then exported to the cytoplasm to be consumed, while cytosolic ADP is imported to the mitochondria for ATP regeneration. The exchange of ADP and ATP across the mitochondrial membrane is mediated by the mitochondrial ADP/ATP carrier, a membrane protein which has been proposed to cycle between two conformationally distinct states, cytosolic-open (c-state) and matrix-open (m-state), thereby shuttling nucleotides across the inner mitochondrial membrane (http://www.ks.uiuc.edu/Research/AdpAtpCarrier/). The c-state of the carrier is the only structurally known state [1]. As a result, conformational changes of the carrier involved in an exchange cycle remained elusive.