Reddy C S K, Ghai R, Kalia V C
Centre for Biochemical Technology (CSIR), Delhi University Campus, Mall Road, Delhi 110 007, India.
Bioresour Technol. 2003 Apr;87(2):137-46. doi: 10.1016/s0960-8524(02)00212-2.
Polyhydroxyalkanoates have gained major importance due to their structural diversity and close analogy to plastics. These are gaining more and more importance world over. Different sources (natural isolates, recombinant bacteria, plants) and other methods are being investigated to exert more control over the quality, quantity and economics of poly(3-hydroxybutyrate) (PHB) production. Their biodegradability makes them extremely desirable substitutes for synthetic plastics. The PHB biosynthetic genes phbA, phbB and phbC are clustered and organized in one phbCAB operon. The PHB pathway is highly divergent in the bacterial genera with regard to orientation and clustering of genes involved. Inspite of this the enzymes display a high degree of sequence conservation. But how similar are the mechanisms of regulation of these divergent operons is as yet unknown. Structural studies will further improve our understanding of the mechanism of action of these enzymes and aid us in improving and selecting better candidates for increased production. Metabolic engineering thereafter promises to bring a feasible solution for the production of "green plastic".
聚羟基脂肪酸酯因其结构多样性以及与塑料的高度相似性而变得极为重要。它们在全球范围内正变得越来越重要。人们正在研究不同的来源（天然分离物、重组细菌、植物）和其他方法，以更好地控制聚（3-羟基丁酸酯）（PHB）生产的质量、数量和经济性。它们的生物可降解性使其成为合成塑料极具吸引力的替代品。PHB生物合成基因phbA、phbB和phbC聚集在一起，并在一个phbCAB操纵子中进行组织。在细菌属中，PHB途径在涉及的基因方向和聚类方面差异很大。尽管如此，这些酶仍表现出高度的序列保守性。但这些不同操纵子的调控机制有多相似，目前尚不清楚。结构研究将进一步增进我们对这些酶作用机制的理解，并帮助我们改进和选择更好的候选物以提高产量。代谢工程随后有望为“绿色塑料”的生产带来可行的解决方案。
