Isolation and characterization of a new acetate-requiring mutant strain, ace-9, of Neurospora crassa.
A new acetate-requiring mutant strain of Neurospora crassa, ace-9, has been isolated. The mutant gene was mapped between nuc-2 and arg-12 on the right arm of the second linkage group. The ace-9 mutant strain shows very weak activity of pyruvate dehydrogenase complex (PDHC). Three strains that show no activity of PDHC had already been found, i.e., ace-2, ace-3, and ace-4. Thus the ace-9 is the fourth gene that causes the deficiency in PDHC activity by a mutation. Deficiency of PDHC activity in ace-9 strain seems to be due to defective E1 component, because (1) the activity of E1 component enzyme is very weak in ace-9 mutant strain, and (2) normal PDHC activity was resumed when a preparation of ace-9 was mixed with E1-E2 fraction of wild type or with E1 component of wild type E. coli. Difference in thermostability of both E1 component enzyme and PDHC between ace-9 and the wild type strains supports this conclusion.
Santosa
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Faculty of Science, Kwansei Gakuin University, Hyogo, Japan.
Kuwana
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H
D000085:Acetates / Q000378:metabolism*; D002874:Chromosome Mapping; D004795:Enzyme Stability; D005800:Genes, Fungal; D009154:Mutation; D009492:Neurospora crassa / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D011768:Pyruvate Dehydrogenase Complex / Q000235:genetics* / Q000378:metabolism; D013696:Temperature
D000085:Acetates; D011768:Pyruvate Dehydrogenase Complex