C-terminal propeptide of the Caldariomyces fumago chloroperoxidase: an intramolecular chaperone?
The Caldariomyces fumago chloroperoxidase (CPO) is synthesised as a 372-aa precursor which undergoes two proteolytic processing events: removal of a 21-aa N-terminal signal peptide and of a 52-aa C-terminal propeptide. The Aspergillus niger expression system developed for CPO was used to get insight into the function of this C-terminal propeptide. A. niger transformants expressing a CPO protein from which the C-terminal propeptide was deleted failed in producing any extracellular CPO activity, although the CPO polypeptide was synthesised. Expression of the full-length gene in an A. niger strain lacking the KEX2-like protease PclA also resulted in the production of CPO cross-reactive material into the culture medium, but no CPO activity. Based on these results, a function of the C-terminal propeptide in CPO maturation is indicated.
Conesa
A
A
TNO Nutrition and Food Research Institute, Department of Applied Microbiology and Gene Technology, P.O. Box 360, 3700 AJ Zeist, The Netherlands.
Weelink
G
G
van den Hondel
C A
CA
Punt
P J
PJ
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics; D001234:Aspergillus niger / Q000235:genetics; D001483:Base Sequence; D002711:Chloride Peroxidase / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004792:Enzyme Precursors / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D018832:Molecular Chaperones / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D011487:Protein Conformation
D017931:DNA Primers; D004792:Enzyme Precursors; D018832:Molecular Chaperones; D002711:Chloride Peroxidase