P. Vandenbroek et al., ISOLATION AND CHARACTERIZATION OF THE GLUCOSE-6-PHOSPHATE-DEHYDROGENASE ENCODING GENE (GSDA) FROM ASPERGILLUS-NIGER, MGG. Molecular & general genetics, 247(2), 1995, pp. 229-239
Genomic and CDNA clones encoding glucose-6-phosphate dehydrogenase (G6
PD) were isolated from the fungus Aspergillus niger. Sequence analysis
of the glucose-6-phosphate dehydrogenase gene (gsdA) revealed an open
reading frame of 1530 bp, encoding a protein of 58,951 kDa. The gsdA
gene is interrupted by nine introns the most proximal of which is exce
ptionally large (348 bp). The region upstream of the ATG contains seve
ral C+T-rich stretches. The two major and one minor transcription star
t points are all located within these regions, In the upstream region
several direct and inverted repeats, but no clear TATA or CCAAT boxes
can be found. A. niger strains overproducing G6PD were constructed by
cotransformation of gsdA subclones. Overexpression of G6PD was shown t
o be deleterious for the fungus, especially when cotransformants were
grown on media containing ammonia. Attempts to construct a gsdA null m
utant by gene disruption were unsuccessful.