Nature. 1987;325(6101):279-81. doi: 10.1038/325279a0.
Cellulose is the most abundant renewable carbon resource on earth and is an indispensable raw material for the wood, paper, and textile industries. A model system to study the mechanism of cellulose biogenesis is the bacterium Acetobacter xylinum which produces pure cellulose as an extracellular product. It was from this organism that in vitro preparations which possessed high levels of cellulose synthase activity were first obtained in both membranous and soluble forms. We recently demonstrated that this activity is subject to a complex multi-component regulatory system, in which the synthase is directly affected by an unusual cyclic nucleotide activator enzymatically formed from GTP, and indirectly by a Ca (2+) -sensitive phosphodiesterase which degrades the activator. The cellulose synthase activator (CSA) has now been identified as bis-(3' 5')-cyclic diguanylic acid (5'G3'p5'G3'p) on the basis of mass spectroscopic data, nuclear magnetic resonance analysis and comparison with chemically synthesized material. We also report here on intermediary steps in the synthesis and degradation of this novel circular dinucleotide, which have been integrated into a model for the regulation of cellulose synthesis.
纤维素是地球上最丰富的可再生碳资源，是木材、纸张和纺织工业不可或缺的原材料。研究纤维素生物合成机制的模式系统是醋酸杆菌，它将纯纤维素作为细胞外产物产生。正是从这种生物体中，首次获得了具有高纤维素合酶活性的体外制剂，既有膜结合形式，也有可溶形式。我们最近证明，这种活性受到一个复杂的多组分调节系统的影响，其中合酶直接受到由 GTP 酶促形成的一种不寻常的环核苷酸激活剂的影响，间接受到 Ca (2+) 敏感的磷酸二酯酶的影响，该磷酸二酯酶降解激活剂。根据质谱数据、核磁共振分析和与化学合成材料的比较，纤维素合酶激活剂（CSA）已被确定为双-(3' 5')-环二鸟苷酸（5'G3'p5'G3'p）。我们还报告了这种新型环状二核苷酸合成和降解的中间步骤，这些步骤已被整合到纤维素合成调节的模型中。
