title: APHO1 from the yeast Arxula adeninivorans encodes an acid phosphatase of broad substrate specificity.
abstract: The extracellular acid phosphatase-encoding Arxula adeninivorans APHO1 gene was isolated using degenerated specific oligonucleotide primers in a PCR screening approach. The gene harbours an ORF of 1449 bp encoding a protein of 483 amino acids with a calculated molecular mass of 52.4 kDa. The sequence includes an N-terminal secretion sequence of 17 amino acids. The deduced amino acid sequence exhibits 54% identity to phytases from Aspergillus awamori, Asp. niger and Asp. ficuum and a more distant relationship to phytases of the yeasts Candida albicans and Debaryomyces hansenii (36-39% identity). The sequence contains the phosphohistidine signature and the conserved active site sequence of acid phosphatases. APHO1 expression is induced under conditions of phosphate limitation. Enzyme isolates from wild and recombinant strains with the APHO1 gene expressed under control of the strong A. adeninivorans-derived TEF1 promoter were characterized. For both proteins, a molecular mass of approx. 350 kDa, corresponding to a hexameric structure, a pH optimum of pH 4.8 and a temperature optimum of 60 degrees C were determined. The preferred substrates include p-nitrophenyl-phosphate, pyridoxal-5-phosphate, 3-indoxyl-phosphate, 1-naphthylphosphate, ADP, glucose-6-phosphate, sodium-pyrophosphate, and phytic acid. Thus the enzyme is a secretory acid phosphatase with phytase activity and not a phytase as suggested by strong homology to such enzymes.
authors.affiliation: Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110 021, India.
authors.forename: Parvinder
authors.initials: P
authors.lastname: Kaur
authors.forename: Anja
authors.initials: A
authors.lastname: Lingner
authors.forename: Bijinder
authors.initials: B
authors.lastname: Singh
authors.forename: Erik
authors.initials: E
authors.lastname: Böer
authors.forename: Jelena
authors.initials: J
authors.lastname: Polajeva
authors.forename: Gerhard
authors.initials: G
authors.lastname: Steinborn
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Bode
authors.forename: Gerd
authors.initials: G
authors.lastname: Gellissen
authors.forename: Tulasi
authors.initials: T
authors.lastname: Satyanarayana
authors.forename: Gotthard
authors.initials: G
authors.lastname: Kunze
mesh_terms: D000135:Acid Phosphatase / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D007700:Kinetics; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D004718:Saccharomycetales / Q000201:enzymology* / Q000235:genetics*; D013379:Substrate Specificity
chemical_list: D004271:DNA, Fungal; D010710:Phosphates; D011994:Recombinant Proteins; D000135:Acid Phosphatase