ISSN:
1573-4927
Keywords:
Aspergillus nidulans
;
DNase A
;
deoxyribonuclease secretion
;
phosphate repression
;
regulator genepalcA
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract High levels of nuclease activities were identified in filtrates ofAspergillus cultures after growth in low- but not in high-phosphate media. Deoxyribonuclease activities, characterized extensively by column chromatography, showed a coincident single peak for ss- and ds-DNase which was distinct from the peak for RNase. Both ss-DNase and ds-DNase are endonucleolytic and showed the highest activity in the presence of Ca2+ and Mn2+ (atpH 8.0). They also showed identical heat sensitivities suggesting that a single, phosphate-repressible DNase was secreted. This enzyme, therefore, corresponds to the well-characterized extracellular DNase A ofNeurospora. However, theAspergillus DNase A did not cross-react with antisera to secretedNeurospora nucleases and showed different chromatographic properties, and active peptides of different sizes were visualized on DNA activity gels. The increasing derepression ofAspergillus DNase A by decreasing phosphate levels was similar to that of secreted alkaline phosphatase and these increases were both abolished by the regulatory mutantpalcA.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00552989
