Formation of 5-aminolevulinate via glutamate-1-semialdehyde and 4,5-dioxovalerate with participation of an RNA component in Scenedesmus obliquus mutant C-2A'.
In the yellow mutant C-2A' of the unicellular green alga Scenedesmus obliquus the participation of an RNA species in the conversion of glutamate to 5-aminolevulinate is clearly demonstrated by the fact that RNAase treatment of a soluble enzyme preparation drastically decreases the formation of 5-aminolevulinate. The involvement of 4,5-dioxovalerate in the C5 pathway is demonstrated by the decrease of label in enzymatically formed 5-aminolevulinate from [14C]glutamate by providing an increased unlabelled pool of 4,5-dioxovalerate. Evidence supporting the role of glutamate-1-semialdehyde as an additional intermediate in the reaction sequence is also presented. We propose a new reaction scheme, consistent with the results reported here, for the formation of 5-aminolevulinate via the C5 pathway.
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Fachbereich Biologie/Botanik, Philipps-Universität, Marburg, F.R.G.
Dörnemann
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D000622:Aminolevulinic Acid / Q000378:metabolism*; D000460:Chlorophyta / Q000235:genetics* / Q000378:metabolism; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology; D005971:Glutamates / Q000378:metabolism*; D007982:Levulinic Acids / Q000378:metabolism*; D009154:Mutation; D012313:RNA / Q000378:metabolism*; D014631:Valerates / Q000378:metabolism*
D003509:Cyclohexanecarboxylic Acids; D005971:Glutamates; D007982:Levulinic Acids; D014631:Valerates; C012987:gabaculine; C007509:4,5-dioxovaleric acid; D012313:RNA; C057794:glutamate-1-semialdehyde; D000622:Aminolevulinic Acid