Liu Y S, Tseng Y H, Lin J W, Weng S F
Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan, Republic of China.
Biochem Biophys Res Commun. 1997 Jun 18;235(2):300-5. doi: 10.1006/bbrc.1997.6778.
The Xanthomonas campestris pv. campestris 17 gene tdh, which codes for the threonine dehydrogenase (TDH), was cloned and sequenced. The deduced gene product, a polypeptide consisting of 340 amino acids (Mr = 37,048), has 63.5% identity to the E. coli TDH in amino acid sequence and shares residue conservation with the alcohol/polyol dehydrogenases from different organisms. TDH activity was not detectable in the tdh mutant constructed by gene replacement; however, the enzyme activity in the mutant complemented in trans by a plasmid containing the complete tdh sequence was increased by 15 folds over Xc17. Northern blot analysis detected an mRNA with a size similar to that of the Xc17 tdh coding region, suggesting that the tdh gene-containing transcript may be monocistronic.
克隆并测序了编码苏氨酸脱氢酶（TDH）的野油菜黄单胞菌野油菜致病变种17基因tdh。推导的基因产物是一种由340个氨基酸组成的多肽（Mr = 37,048），其氨基酸序列与大肠杆菌TDH有63.5%的同一性，并且与来自不同生物体的醇/多元醇脱氢酶有保守残基。在通过基因置换构建的tdh突变体中未检测到TDH活性；然而，通过含有完整tdh序列的质粒反式互补的突变体中的酶活性比Xc17增加了15倍。Northern印迹分析检测到一种大小与Xc17 tdh编码区相似的mRNA，表明含tdh基因的转录本可能是单顺反子的。
