Secreted glutamic protease rescues aspartic protease Pep deficiency in Aspergillus fumigatus during growth in acidic protein medium.
Details
Serval ID
serval:BIB_7635EE1ACA3D
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Secreted glutamic protease rescues aspartic protease Pep deficiency in Aspergillus fumigatus during growth in acidic protein medium.
Journal
Microbiology
ISSN
1465-2080 (Electronic)
ISSN-L
1350-0872
Publication state
Published
Issued date
2011
Volume
157
Number
5
Pages
1541-1550
Language
english
Abstract
In an acidic protein medium Aspergillus fumigatus secretes an aspartic endoprotease (Pep) as well as tripeptidyl-peptidases, a prolyl-peptidase and carboxypeptidases. In addition, LC-MS/MS revealed a novel glutamic protease, AfuGprA, homologous to Aspergillus niger aspergillopepsin II. The importance of AfuGprA in protein digestion was evaluated by deletion of its encoding gene in A. fumigatus wild-type D141 and in a pepΔ mutant. Either A. fumigatus Pep or AfuGprA was shown to be necessary for fungal growth in protein medium at low pH. Exoproteolytic activity is therefore not sufficient for complete protein hydrolysis and fungal growth in a medium containing proteins as the sole nitrogen source. Pep and AfuGprA constitute a pair of endoproteases active at low pH, in analogy to A. fumigatus alkaline protease (Alp) and metalloprotease I (Mep), where at least one of these enzymes is necessary for fungal growth in protein medium at neutral pH. Heterologous expression of AfuGprA in Pichia pastoris showed that the enzyme is synthesized as a preproprotein and that the propeptide is removed through an autoproteolytic reaction at low pH to generate the mature protease. In contrast to A. niger aspergillopepsin II, AfuGprA is a single-chain protein and is structurally more similar to G1 proteases characterized in other non-Aspergillus fungi.
Keywords
Acids/metabolism, Amino Acid Sequence, Aspartic Acid Proteases/chemistry, Aspartic Acid Proteases/genetics, Aspergillus fumigatus/enzymology, Aspergillus fumigatus/growth & development, Culture Media/chemistry, Culture Media/metabolism, Fungal Proteins/chemistry, Fungal Proteins/genetics, Glutamic Acid/metabolism, Hydrogen-Ion Concentration, Molecular Sequence Data, Peptide Hydrolases/chemistry, Peptide Hydrolases/genetics, Protein Transport
Pubmed
Web of science
Open Access
Yes
Create date
22/03/2011 16:17
Last modification date
20/08/2019 15:33