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Molecular characterization and expression analysis of a phosphoserine aminotransferase involving l ‐serine synthesis from silkworm, Bombyx mori
Author(s) -
Haque Mohammad R.,
Hirowatari Aiko,
Koyanagi Ayumi,
Ichinose Takashi,
Abiru Maiko,
Mohri Shinya,
Furuya Shigeki,
Yamamoto Kohji
Publication year - 2019
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.21553
Subject(s) - bombyx mori , biology , serine , biochemistry , complementary dna , bombyx , microbiology and biotechnology , messenger rna , recombinant dna , escherichia coli , phosphoserine , enzyme , gene
In this study, we identified and characterized a phosphoserine aminotransferase (bmPSAT) from Bombyx mori ( B. mori ) that is responsible for l ‐serine biosynthesis. A complementary DNA that encodes bmPSAT was cloned by reverse transcriptase polymerase reaction and sequenced. The presumed amino acid sequence revealed 47–87% identity with known PSATs from insects, humans, plants, and bacteria. Through phylogenetic analysis, we found that bmPSAT is evolutionary related to insect PSATs. Recombinant bmPSAT was produced in Escherichia coli by using a cold‐shock promotor and purified to homogeneity. This enzyme utilizes phosphohydroxypyruvate and glutamate for transamination. bmPSAT messenger RNA (mRNA) was expressed at higher levels in several tissues of standard strain silkworm including the silk gland, whereas a sericin‐deficient silkworm strain exhibited a diminished expression of bmPSAT mRNA in the silk gland. These findings indicate that bmPSAT may play an important role in synthesizing and supplying l ‐serine in the larva of B. mori .