Charnetzky W T, Mortlock R P
J Bacteriol. 1974 Jul;119(1):170-5. doi: 10.1128/jb.119.1.170-175.1974.
Klebsiella aerogenes strain W70 has an inducible pathway for the degradation of d-arabitol which is comparable to the one found in Aerobacter aerogenes strain PRL-R3. The pathway is also similar to the pathway of ribitol catabolism in that it is composed of a pentitol dehydrogenase, d-arabitol dehydrogenase (ADH), and a pentulokinase, d-xylulokinase (DXK). These two enzymes are coordinately controlled and induced in response to d-arabitol, the apparent inducer of synthesis of these enzymes. We obtained mutants which lacked a functional d-xylose pathway and were constitutive for the ribitol catabolic pathway. These mutants were able to grow on the unusual pentitol, xylitol, only if they contained the functional DXK of the d-arabitol pathway. This provided us with a specific selection technique for DXK(+) transductants. As in A. aerogenes, mutants constitutive for ADH were able to use this enzyme to convert the hexitol d-mannitol to d-fructose. With mutants blocked in the normal d-mannitol catabolic pathway, growth on d-mannitol became a test for ADH constitutivity. Growth of such mutants on xylitol, d-arabitol, and d-mannitol was utilized to classify transductants in mapping, by transductional analysis, the loci involved in d-arabitol utilization. Three-point crosses gave the order dalK-dalD-dalC, where dalK is the DXK structural gene, dalD is the ADH structural gene, and dalC is a regulatory site controlling synthesis of both enzymes.
产气克雷伯菌菌株W70具有一条诱导型的d-阿拉伯糖醇降解途径，该途径与产气气杆菌菌株PRL-R3中的途径类似。该途径也与核糖醇分解代谢途径相似，因为它由一种戊糖醇脱氢酶、d-阿拉伯糖醇脱氢酶（ADH）和一种戊酮糖激酶、d-木酮糖激酶（DXK）组成。这两种酶受到协调控制，并在d-阿拉伯糖醇（这些酶合成的明显诱导物）的作用下被诱导。我们获得了缺乏功能性d-木糖途径且核糖醇分解代谢途径组成型表达的突变体。这些突变体只有在含有d-阿拉伯糖醇途径的功能性DXK时，才能在不常见的戊糖醇木糖醇上生长。这为我们提供了一种筛选DXK(+)转导子的特异性选择技术。与产气气杆菌一样，ADH组成型的突变体能够利用这种酶将己糖醇d-甘露糖醇转化为d-果糖。对于正常d-甘露糖醇分解代谢途径受阻的突变体，在d-甘露糖醇上的生长成为ADH组成型的检测方法。利用这些突变体在木糖醇、d-阿拉伯糖醇和d-甘露糖醇上的生长情况，通过转导分析对参与d-阿拉伯糖醇利用的基因座进行定位，从而对转导子进行分类。三点杂交得出dalK-dalD-dalC的顺序，其中dalK是DXK结构基因，dalD是ADH结构基因，dalC是控制这两种酶合成的调控位点。
