D-Arabitol catabolic pathway in Klebsiella aerogenes.
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.
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D001089:Arabinose; D002238:Carbohydrate Epimerases / Q000378:metabolism; D002364:Caseins; D002474:Cell-Free System; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D003470:Culture Media; D004754:Enterobacter / Q000378:metabolism; D004790:Enzyme Induction; D007709:Klebsiella / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism; D009154:Mutation; D010770:Phosphotransferases / Q000378:metabolism; D013053:Spectrophotometry; D013237:Stereoisomerism; D013402:Sugar Alcohols / Q000378:metabolism*; D013403:Sugar Phosphates / Q000096:biosynthesis; D014161:Transduction, Genetic; D014993:Xylitol / Q000378:metabolism; D014994:Xylose / Q000378:metabolism
D002364:Caseins; D003470:Culture Media; D013402:Sugar Alcohols; D013403:Sugar Phosphates; D008353:Mannitol; D014994:Xylose; D001089:Arabinose; D000429:Alcohol Oxidoreductases; D010770:Phosphotransferases; D002238:Carbohydrate Epimerases; D014993:Xylitol