Division of Biochemical Sciences, National Chemical Laboratory, Pune, 411008, India.
Biochem Genet. 2013 Oct;51(9-10):737-49. doi: 10.1007/s10528-013-9603-z. Epub 2013 Jun 8.
Alkaline xylanase C from the alkaliphilic Bacillus sp. (NCL 87-6-10) has a low molecular weight and alkaline pI and is cellulase-free, properties compatible with its use in the prebleaching of pulp. We report here the cloning and sequence analysis of three variants of the gene encoding xylanase C; xyl C1, xyl C2, and xyl C3. In phylogenetic analysis, the three xylanase C variants clustered into a single group along with other reported alkaline xylanases. Residues contributing to the alkaline pH were present in all three variants. DNA and protein sequence comparison of these variants with other reported alkaline xylanases revealed silent mutations, some of which are due to codon preference in the respective organisms. The recombinant Xyl C1 that was successfully expressed in E. coli BL21 (DE3) had properties similar to the native enzyme.
来自嗜碱芽孢杆菌（NCL 87-6-10）的碱性木聚糖酶 C 具有低分子量和碱性等电点，且不含纤维素酶，这些特性使其适用于纸浆的预漂白。我们在此报告编码木聚糖酶 C 的三个基因变体（xyl C1、xyl C2 和 xyl C3）的克隆和序列分析。在系统发育分析中，这三种木聚糖酶 C 变体与其他报道的碱性木聚糖酶一起聚集在一个单一的组中。所有三种变体中都存在有助于碱性 pH 的残基。这些变体与其他报道的碱性木聚糖酶的 DNA 和蛋白质序列比较显示出沉默突变，其中一些是由于各自生物体中密码子偏好造成的。在大肠杆菌 BL21（DE3）中成功表达的重组 Xyl C1 具有与天然酶相似的性质。
