Ya-lin LIU, Yun-hao ZHU, Zhi-wei SHENG, et al. Cloning and Expression Analysis of PaAACT Gene from Phytolacca americana. [J]. Chinese Journal of Experimental Traditional Medical Formulae 25(21):124-131(2019)
DOI:
Ya-lin LIU, Yun-hao ZHU, Zhi-wei SHENG, et al. Cloning and Expression Analysis of PaAACT Gene from Phytolacca americana. [J]. Chinese Journal of Experimental Traditional Medical Formulae 25(21):124-131(2019) DOI: 10.13422/j.cnki.syfjx.20192113.
Cloning and Expression Analysis of PaAACT Gene from Phytolacca americana
To clone the key enzyme gene involved in the biosynthesis of esculentoside A(EsA)
acetoacetyl-CoA transferase(AACT) gene was cloned from
Phytolacca americana
for bioinformatics analysis and prokaryotic expression.
Method:
2
Total RNA was extracted from the root of
P
.
americana
and then cDNA was synthesized through the reverse transcription. Based on analysis of the transcriptome data of
P
.
americana
the specific primers of
PaAACT
gene were designed
and the cDNA sequence of
PaAACT
gene was amplified by polymerase chain reaction(PCR) method. Prokaryotic induction
expression and purification of the target protein were induced through the construction of the prokaryotic expression vector pET-32a-PaAACT.
Result:
2
The open reading frame (ORF) of
PaAACT
gene was 1 254 bp
and encoded 417 amino acid residues. Bioinformatic analysis showed that the molecular formula of PaAACT protein was C
1 914
H
3 120
N
538
O
576
S
17
inferring that its molecular weight was 43.43 kDa
the theoretical isoelectric point was 8.90
and the instability index of PaAACT protein was 32.27
which was a stable protein. According to bioinformatics analysis
PaAACT protein was a member of the thiolase family and contained one conserved site and one active site of the thiolase family at the C-terminal. PaAACT protein may be located in the cytoplasm
without a signal peptide or transmembrane domain. The phylogenetic analysis indicated that PaAACT protein showed the highest homology with AACT protein from polygonaceae plants (such as
Beta vulgaris
). The recombinant PaAACT protein was successfully expressed in
Escherichia coli
BL21(DE3) strain through IPTG induction
and the purified target protein was obtained by Ni
2+
affinity chromatography.
Conclusion:
2
In this study
the
PaAACT
gene was cloned from
P
.
americana
which lays a foundation for further determination of enzyme activity assay of PaAACT and preparation of antibody
and provides the theoretical basis for studying its role in the biosynthesis pathway of EsA.
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