Molecular characterization and expression analysis of a phosphoserine aminotransferase involving l‐serine synthesis from silkworm, Bombyx mori. Issue 2 (19th April 2019)

• Record Type: Journal Article
• Authors: Haque, Mohammad R.; Hirowatari, Aiko; Koyanagi, Ayumi; Ichinose, Takashi; Abiru, Maiko; Mohri, Shinya; Furuya, Shigeki; Yamamoto, Kohji
• Is Part Of: Archives of insect biochemistry and physiology. Volume 101:Issue 2(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-04-19
• Subjects: Bombyx mori -- phosphoserine aminotransferase -- serine -- silkworm; Insects -- Physiology -- Periodicals; Insect biochemistry -- Periodicals; 595.701572
• DOI: 10.1002/arch.21553
• Languages: English
• ISSNs: 0739-4462

Abstract

Abstract: In this study, we identified and characterized a phosphoserine aminotransferase (bmPSAT) from Bombyx mori ( B. mori ) that is responsible forl ‐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 supplyingl ‐serine in the larva of B. mori . Abstract : The black and green boxes indicate the glutamate‐, and PLP‐binding sites, respectively. The sites are highly conserved in amino acid sequence of PSAT.