Reusch Rosetta N
Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
Int J Mol Sci. 2013 May 23;14(6):10727-48. doi: 10.3390/ijms140610727.
Poly-(R)-3-hydroxybutyrate (PHB), a linear polymer of R-3-hydroxybutyrate (R-3HB), is a fundamental constituent of biological cells. Certain prokaryotes accumulate PHB of very high molecular weight (10,000 to >1,000,000 residues), which is segregated within granular deposits in the cytoplasm; however, all prokaryotes and all eukaryotes synthesize PHB of medium-chain length (~100-200 residues) which resides within lipid bilayers or lipid vesicles, and PHB of short-chain length (<12 residues) which is conjugated to proteins (cPHB), primarily proteins in membranes and organelles. The physical properties of cPHB indicate it plays important roles in the targeting and folding of cPHB-proteins. Here we review the occurrence, physical properties and molecular characteristics of cPHB, and discuss its influence on the folding and structure of outer membrane protein A (OmpA) of Escherichia coli.
聚（R）-3-羟基丁酸酯（PHB）是R-3-羟基丁酸酯（R-3HB）的线性聚合物，是生物细胞的基本组成成分。某些原核生物会积累高分子量（10,000至>1,000,000个残基）的PHB，这些PHB在细胞质中的颗粒沉积物中分离；然而，所有原核生物和所有真核生物都会合成中等链长（约100-200个残基）的PHB，其存在于脂质双层或脂质小泡中，以及短链长（<12个残基）的PHB，其与蛋白质（cPHB）结合，主要是膜和细胞器中的蛋白质。cPHB的物理性质表明它在cPHB蛋白的靶向和折叠中起重要作用。在此，我们综述了cPHB的存在、物理性质和分子特征，并讨论了其对大肠杆菌外膜蛋白A（OmpA）折叠和结构的影响。
