Molecular cloning and sequence analysis of a PVGOX gene encoding glucose oxidase in Penicillium viticola F1 strain and it's expression quantitation

Molecular cloning and sequence analysis of a PVGOX gene encoding glucose oxidase in Penicillium viticola F1 strain and it's expression quantitation

Abstract

The PVGOX gene (accession number: KT452630) was isolated from genomic DNA of the marine fungi Penicillium
viticola F1 by GenomeWalking and their expression analysis was done by Fluorescent RT-PCR. An open reading
frame of 1806 bp encoding a 601 amino acid protein (isoelectric point: 5.01) with a calculatedmolecular weight
of 65,535.4 was characterized. The deduced protein showed 75%, 71%, 69% and 64% identity to those deduced
from the glucose oxidase (GOX) genes from different fungal strains including; Talaromyces variabilis, Beauveria
bassiana, Aspergillus terreus, and Aspergillus niger, respectively. The promoter of the gene (intronless) had two
TATA boxes around the base pair number−88 and −94 and as well as a CAAT box at−100. However, the terminator
of the PVGOX gene does not contain any polyadenylation site (AATAAA). The protein deduced from the
PVGOX gene had a signal peptide containing 17 amino acids, three cysteine residues and six potential N-linked
glycosylation sites, among them, −N-K-T-Y- at 41 amino acid, −N-R-S-L- at 113 amino acid, −N-G-T-I- at
192 amino acid, −N-T-T-A at 215 amino acid, −N-F-T-E at 373 amino acid and –N-V-T-A- at 408 amino acid
were the most possible N-glycosylation sites. Furthermore, the relative transcription level of the PVGOX gene
was also stimulated in the presence of 4% (w/v) of calcium carbonate and 0.5 % (v/v) of CSL in the production
medium compared with that of the PVGOX gene when the fungal strain F1 was grown in the absence of calcium
carbonate and CSL in the productionmedium, suggesting that under the optimal conditions, the expression of the
PVGOX gene responsible for gluconic acid biosynthesis was enhanced, leading to increased gluconic acid
production. Therefore, the highly glycosylated oxidase enzyme produced by P. viticola F1 strain might be a
good producer in the fermentation process for the industrial level production of gluconic acid.

No. of Pages
291-302
Volume
592
Author's Details
Ibrar Khan, Sadia Qayyum, Shehzad Ahmed, Zeeshan Niaz, Nighat Fatima, Zhen-Ming Chi
Research Field
Microbiology