Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, Japan.
Enzyme Microb Technol. 2013 Jan 10;52(1):38-43. doi: 10.1016/j.enzmictec.2012.10.004. Epub 2012 Oct 13.
Bacterial genes for the degradation of major dilignols produced in lignifying xylem are expected to be useful tools for the structural modification of lignin in plants. For this purpose, we isolated pinZ involved in the conversion of pinoresinol from Sphingobium sp. strain SYK-6. pinZ showed 43-77% identity at amino acid level with bacterial NmrA-like proteins of unknown function, a subgroup of atypical short chain dehydrogenases/reductases, but revealed only 15-21% identity with plant pinoresinol/lariciresinol reductases. PinZ completely converted racemic pinoresinol to lariciresinol, showing a specific activity of 46±3 U/mg in the presence of NADPH at 30°C. In contrast, the activity for lariciresinol was negligible. This substrate preference is similar to a pinoresinol reductase, AtPrR1, of Arabidopsis thaliana; however, the specific activity of PinZ toward (±)-pinoresinol was significantly higher than that of AtPrR1. The role of pinZ and a pinZ ortholog of Novosphingobium aromaticivorans DSM 12444 were also characterized.
预计细菌中用于降解木质素形成过程中产生的主要二芳基化合物的基因，将成为植物木质素结构修饰的有用工具。为此，我们从鞘氨醇单胞菌 SYK-6 中分离出参与松柏醇转化的 pinZ。pinZ 与未知功能的细菌 NmrA 样蛋白（非典型短链脱氢酶/还原酶的一个亚组）在氨基酸水平上具有 43-77%的同源性，但与植物松柏醇/落叶松醇还原酶的同源性仅为 15-21%。PinZ 可完全将外消旋松柏醇转化为落叶松醇，在 30°C 下 NADPH 存在时的比活为 46±3 U/mg。相比之下，落叶松醇的活性可以忽略不计。这种底物偏好类似于拟南芥的松柏醇还原酶 AtPrR1；然而，PinZ 对（±）-松柏醇的比活显著高于 AtPrR1。pinZ 和 Novosphingobium aromaticivorans DSM 12444 的 pinZ 同源物的作用也得到了表征。
