Valla S, Coucheron D H, Fjaervik E, Kjosbakken J, Weinhouse H, Ross P, Amikam D, Benziman M
Laboratory of Biotechnology, Norwegian Institute of Technology, Trondheim.
Mol Gen Genet. 1989 May;217(1):26-30. doi: 10.1007/BF00330938.
Three cellulose-negative (Cel-) mutants of Acetobacter xylinum strain ATCC 23768 were complemented by a cloned 2.8 kb DNA fragment from the wild type. Biochemical analysis of the mutants showed that they were deficient in the enzyme uridine 5'-diphosphoglucose (UDPG) pyrophosphorylase. The analysis also showed that the mutants could synthesize beta(1-4)-glucan in vitro from UDPG, but not in vivo from glucose. This result was expected, since UDPG is known to be the precursor for cellulose synthesis in A. xylinum. In order to analyze the function of the cloned gene in more detail, its biological activity in Escherichia coli was studied. These experiments showed that the cloned fragment could be used to complement an E. coli mutant deficient in the structural gene for UDPG pyrophosphorylase. It is therefore clear that the cloned fragment must contain this gene from A. xylinum. This is to our knowledge the first example of the cloning of a gene with a known function in cellulose biosynthesis from any organism, and we suggest the gene be designated celA.
木醋杆菌属木醋杆菌菌株ATCC 23768的三个纤维素阴性（Cel-）突变体由野生型的一个克隆的2.8 kb DNA片段进行了互补。对这些突变体的生化分析表明，它们缺乏尿苷5'-二磷酸葡萄糖（UDPG）焦磷酸化酶。分析还表明，这些突变体能够在体外由UDPG合成β(1-4)-葡聚糖，但不能在体内由葡萄糖合成。这个结果是意料之中的，因为已知UDPG是木醋杆菌中纤维素合成的前体。为了更详细地分析克隆基因的功能，研究了其在大肠杆菌中的生物学活性。这些实验表明，克隆片段可用于互补UDPG焦磷酸化酶结构基因缺陷的大肠杆菌突变体。因此很明显，克隆片段必定包含来自木醋杆菌的该基因。据我们所知，这是从任何生物体中克隆出在纤维素生物合成中具有已知功能基因的首个实例，我们建议将该基因命名为celA。
