Evidence for N- and C-terminal processing of a plant defense-related enzyme: Primary structure of tobacco prepro-beta-1,3-glucanase.
Evidence for N- and C-terminal processing of a plant defense-related enzyme: Primary structure of tobacco prepro-beta-1,3-glucanase.
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植物防御相关酶的 N 端和 C 端加工的证据：烟草前原 β-1,3-葡聚糖酶的一级结构。
DOI：
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发表时间：
1988
影响因子：
11.1
通讯作者：
F. Meins
中科院分区：
文献类型：
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作者：
H. Shinshi;H. Wenzler;J. Neuhaus;G. Felix;J. Hofsteenge;F. Meins
烟草葡聚糖内切-1，3-β-葡糖苷酶（β-1，3-葡聚糖酶; 1，3-β-D-葡聚糖葡聚糖水解酶; EC 3.2.1.39）表现出复杂的激素和发育调节，并且当植物被病原体感染时被诱导。我们从5个部分cDNA克隆的核苷酸序列和5个肽的氨基酸序列确定了这种酶的一级结构，所述肽共覆盖70个残基。β-1，3-葡聚糖酶作为359个残基的前酶原产生，具有21个残基的N-末端疏水信号肽和含有推定的N-糖基化位点的22个残基的C-末端延伸。用衣霉素进行的脉冲追踪实验的结果证明，加工的第一步是信号肽的丢失和寡糖侧链的添加。糖基化中间体进一步加工，失去寡糖侧链和C-末端延伸，得到成熟酶。cDNA克隆和成熟蛋白序列中的杂合性以及限制性内切酶片段的Southern印迹分析表明烟草β-1，3-葡聚糖酶由一个小基因家族编码。这个家族的两个或三个成员似乎在烟草的每一个祖先中都有其进化起源，Nicotiana sylvestris和Nicotiana tomentosiformis。
Tobacco glucan endo-1,3-beta-glucosidase (beta-1,3-glucanase; 1,3-beta-D-glucan glucanohydrolase; EC 3.2.1.39) exhibits complex hormonal and developmental regulation and is induced when plants are infected with pathogens. We determined the primary structure of this enzyme from the nucleotide sequence of five partial cDNA clones and the amino acid sequence of five peptides covering a total of 70 residues. beta-1,3-Glucanase is produced as a 359-residue preproenzyme with an N-terminal hydrophobic signal peptide of 21 residues and a C-terminal extension of 22 residues containing a putative N-glycosylation site. The results of pulse-chase experiments with tunicamycin provide evidence that the first step in processing is loss of the signal peptide and addition of an oligosaccharide side chain. The glycosylated intermediate is further processed with the loss of the oligosaccharide side chain and C-terminal extension to give the mature enzyme. Heterogeneity in the sequences of cDNA clones and of mature protein and in Southern blot analysis of restriction endonuclease fragments indicates that tobacco beta-1,3-glucanase is encoded by a small gene family. Two or three members of this family appear to have their evolutionary origin in each of the progenitors of tobacco, Nicotiana sylvestris and Nicotiana tomentosiformis.