A melon genomic library was used to isolate and characterize a clone of genomic DNA coding for ascorbate
oxidase (AO) which is considered a key enzyme in the biodegradation of ascorbic acid (AA).
The screening of genomic library was performed by using two probes: AO-PCR product and αE/CMAO3. Seven
clones of recombinant phage, with positive signal, were isolated. The extracted DNA was digested with EcoRI,
Sal I and Bam HI and the combinations among these restriction enzymes. Four clones of AO gene were isolated:
AO1; AO2; AO3 and AO4. Since only clone AO4 had not been characterized so far, the sequencing of this clone
was performed. The isolated sequence of DNA has a length of 3072 bp being bordered at both ends by EcoRI
enzymes.
The comparison between genomic DNA for AO4 in melon and DNA for AO in cucumber revealed a high
similarity (94.45%).
