ANALYSIS OF POLYHYDROXYALKANOATE INCLUSION BIOGENESIS

这个子项目是许多利用 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 中心，但不一定是研究者所在的机构。 本研究的目的是阐明聚羟基脂肪酸酯包合物的生物成因机制。 聚羟基链烷酸酯（PHA）是细菌聚合物，当碳水平高而另一种必需营养素（如氮）有限时，它们在内含物中合成。 PHA具有相当大的商业利益，因为它们包含可形成为可生物降解的塑料的聚酯家族。电子显微镜的研究一直无法解决PHA包涵体的结构，这抑制了运动的包容物生物成因的凝聚力模型。采用原子力显微镜，我们已经确定，有三层结构，外层是膜双层的厚度，中间的网络层，和下面的结晶层状层。遗传学研究表明，中间网络至少部分由PhaP组成，并且PhaP可能易位到周质。因此，似乎可以通过蛋白质和/或蛋白质移动到周质并通过细胞质膜出芽进入细胞质，促进细胞质膜作为包膜的获得，发生包涵体生物发生。

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 goal of this research is to elucidate the mechanism of polyhydroxyalkanoate inclusion biogenesis. Polyhydroxyalkanoates (PHAs) are bacterial polymers that are synthesized in inclusions when carbon levels are high and another essential nutrient, such as nitrogen is limited. There is considerable commercial interest in PHAs because they comprise a family of polyesters that can be formed into plastics that are biodegradable. Electron microscopy studies have been unable to resolve the structure of PHA inclusions and this has inhibited movement toward a cohesive model of inclusion biogenesis. Employing atomic force microscopy, we have determined that there are three layers of structure, an outer envelope that is the thickness of a membrane bilayer, a middle network layer, and an underlying crystalline lamellar layer. Genetic studies have indicated that the middle network is comprised at least partially of PhaP and that PhaP is likely to be translocated to the periplasm. Thus, it would appear that inclusion biogenesis may occur by movement of protein and/or proteins to the periplasm and budding through the cytoplasmic membrane into the cytoplasm, facilitating the acquisition of the cytoplasmic membrane as an envelope.