Plasmid construction
Genomic DNA was purified from S. coelicolor cells grown in
yeast extract-malt extract (YEME) containing 34% sucrose, 1% glucose
and 0.5% MgCl2 at 30 C as described by Hopwood et al. [10].
The concentration of genomic DNA was measured in a UV spectrophotometer
(at 260 nm). The size of genomic DNA was analyzed on
1% agarose gels. The forward primer (ADA-1: 50-TTTAAGCTTCATATG
ACGAGCCGAAGCACCGAG-30 , where the underline indicates
the added HindIII and NdeI linkers) and the reverse primer (ADA-
2: 50-TTTAGATCTTCAGCCGTCG GATTCCGAAGA-30 , where the
underline indicates the added BglII linker) were designed according
to the putative adenosine deaminase gene sequence from S. coelicolor
(Genebank Accession No. SCO4901). The complete coding region
of the gene was amplified by PCR with ADA-1 and ADA-2
primers, using chromosomal DNA prepared from S. coelicolor as
the template and Taq DNA polymerase. PCR was performed as follows:
initial denaturing at 93 C for 5 min; 30 cycles of denaturation
at 93 C for 1 min, annealing at 68 C for 1 min, and
additional extension at 72 C for 1.5 min, and additional extension
at 72 C for 10 min. The PCR product was gel purified with a PCR
purification kit (Qiagen) and ligated into the pGEM-T vector (Promega).
After transformation into competent E. coli JM109, recombinant
plasmid, pGEM-ada, was purified from positive clones by the
alkali method and sequenced to confirm that no mutations were
introduced by the PCR amplification step. After a double digestion
of pGEM-ada with NdeI and BglII, the 1.2 kb fragment was gel purified
and ligated into pET-15b, which had been previously double
digested with NdeI and BamHI. The ligation mixture was transformed
into E. coli BL21 (DE3) and selected on LB containing
60 lg/ml ampicillin.
Plasmid construction
Genomic DNA was purified from S. coelicolor cells grown in
yeast extract-malt extract (YEME) containing 34% sucrose, 1% glucose
and 0.5% MgCl2 at 30 C as described by Hopwood et al. [10].
The concentration of genomic DNA was measured in a UV spectrophotometer
(at 260 nm). The size of genomic DNA was analyzed on
1% agarose gels. The forward primer (ADA-1: 50-TTTAAGCTTCATATG
ACGAGCCGAAGCACCGAG-30 , where the underline indicates
the added HindIII and NdeI linkers) and the reverse primer (ADA-
2: 50-TTTAGATCTTCAGCCGTCG GATTCCGAAGA-30 , where the
underline indicates the added BglII linker) were designed according
to the putative adenosine deaminase gene sequence from S. coelicolor
(Genebank Accession No. SCO4901). The complete coding region
of the gene was amplified by PCR with ADA-1 and ADA-2
primers, using chromosomal DNA prepared from S. coelicolor as
the template and Taq DNA polymerase. PCR was performed as follows:
initial denaturing at 93 C for 5 min; 30 cycles of denaturation
at 93 C for 1 min, annealing at 68 C for 1 min, and
additional extension at 72 C for 1.5 min, and additional extension
at 72 C for 10 min. The PCR product was gel purified with a PCR
purification kit (Qiagen) and ligated into the pGEM-T vector (Promega).
After transformation into competent E. coli JM109, recombinant
plasmid, pGEM-ada, was purified from positive clones by the
alkali method and sequenced to confirm that no mutations were
introduced by the PCR amplification step. After a double digestion
of pGEM-ada with NdeI and BglII, the 1.2 kb fragment was gel purified
and ligated into pET-15b, which had been previously double
digested with NdeI and BamHI. The ligation mixture was transformed
into E. coli BL21 (DE3) and selected on LB containing
60 lg/ml ampicillin.
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