DNA cloning and sequencing
The PCR amplicons were ligated into pGEM-T Easy Vector (Promega, Madison, WI) using T4 DNA ligase.The recombinant plasmids were transformed into competent cells (Escherichia coli DH5α strain), and then the recombinant plasmids were screened using the bluewhite colonies system. The colonies suspected to contain the insert gene were cultured, and the plasmid DNA was extracted using the Invisorb® Spin Plasmid Mini kit (STRATEC molecular GmbH, Berlin, Germany) according to the manufacturer’s instructions. The purified plasmids were sequenced by 1st Base Laboratories, Malaysia.