Knight M E, Halpin C, Schuch W
ICI Seeds, Plant Biotechnology Section, Bracknell, UK.
Plant Mol Biol. 1992 Aug;19(5):793-801. doi: 10.1007/BF00027075.
Cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) is an enzyme involved in lignin biosynthesis. We have previously isolated pure CAD enzyme as two closely related polypeptides of 44 and 42.5 kDa from tobacco stems. In this paper, we report partial amino acid sequences of these two polypeptides. Based on the peptide sequences mixed oligonucleotides were used to screen a tobacco stem cDNA library and CAD cDNA clones encoding the two polypeptides were identified. DNA sequence comparisons indicate very high sequence identity between these clones both in the coding and in the 5' and 3' untranslated sequences. The close similarity between the two CAD genes leads us to suggest that they do not represent different isoforms but are the same gene from each of the two parental lines of Nicotiana tabacum cv. Samsun. Sequence comparisons with alcohol dehydrogenase 1 (ADH1) from yeast shows sequence similarities of ca. 30%, while comparisons with maize, barley and potato ADH1 sequences show similarities of not more than 23%.
肉桂醇脱氢酶（CAD，EC 1.1.1.195）是一种参与木质素生物合成的酶。我们之前从烟草茎中分离出了纯的CAD酶，它是由44 kDa和42.5 kDa的两种密切相关的多肽组成。在本文中，我们报道了这两种多肽的部分氨基酸序列。基于这些肽序列，混合寡核苷酸被用于筛选烟草茎cDNA文库，并鉴定出了编码这两种多肽的CAD cDNA克隆。DNA序列比较表明，这些克隆在编码区以及5'和3'非翻译区都具有非常高的序列同一性。这两个CAD基因之间的高度相似性使我们认为它们并非代表不同的同工型，而是来自烟草品种萨姆逊（Nicotiana tabacum cv. Samsun）两个亲本系的同一个基因。与酵母乙醇脱氢酶1（ADH1）的序列比较显示约30%的序列相似性，而与玉米、大麦和马铃薯ADH1序列的比较显示相似性不超过23%。
