Cluness M J, Turner P D, Clements E, Brown D T, O'Reilly C
School of Health Sciences, University of Sunderland, Tyne and Wear, UK.
J Gen Microbiol. 1993 Aug;139(8):1807-15. doi: 10.1099/00221287-139-8-1807.
The filamentous fungus Fusarium lateritium is cyanide tolerant, due, at least in part, to the induction by cyanide of the enzyme formamide hydrolyase (EC 4.2.1.66). This enzyme, more commonly known as cyanide hydratase, catalyses the hydration of cyanide to formamide. The enzyme was purified from F. lateritium and showed a subunit molecular mass of 43 kDa (as judged by SDS-PAGE), while the native protein appeared to form aggregates of up to 1217 kDa (as judged by gel-filtration and non-denaturing PAGE). mRNA samples from cultures grown with and without cyanide were in vitro translated and immunoprecipitated. This demonstrated that, in this species, the gene encoding the enzyme designated chy1, is cyanide inducible. Differential screening was used to isolate a cyanide hydratase cDNA clone which was subsequently used to obtain the corresponding genomic clone. A fragment of the cDNA clone encoding all but the first seven amino acids of the protein was expressed in E. coli using the expression vector pGEX-2T. Features of F. lateritium cyanide hydratase together with an analysis of the nucleotide sequence encoding this enzyme are presented.
丝状真菌砖红镰孢菌具有耐氰能力，至少部分原因是氰化物可诱导甲酰胺水解酶（EC 4.2.1.66）的产生。这种酶，更常见的名称是氰化物水合酶，催化氰化物水合形成甲酰胺。该酶从砖红镰孢菌中纯化得到，其亚基分子量为43 kDa（通过SDS-PAGE判断），而天然蛋白似乎形成了高达1217 kDa的聚集体（通过凝胶过滤和非变性PAGE判断）。对在有氰化物和无氰化物条件下培养的菌株的mRNA样本进行体外翻译和免疫沉淀。这表明，在该物种中，编码该酶的基因chy1是氰化物可诱导的。通过差异筛选分离出一个氰化物水合酶cDNA克隆，随后用其获得相应的基因组克隆。使用表达载体pGEX-2T在大肠杆菌中表达了该cDNA克隆中除蛋白质前七个氨基酸以外的编码片段。本文介绍了砖红镰孢菌氰化物水合酶的特性以及对编码该酶的核苷酸序列的分析。
