title: A serine hydroxymethyltransferase from marine bacterium Shewanella algae: Isolation, purification, characterization and l-serine production.
abstract: Currently, l-serine is mainly produced by enzymatic conversion, in which serine hydroxymethyltransferase (SHMT) is the key enzyme, suggesting the importance of searching for a SHMT with high activity. Shewanella algae, a methanol-utilizing marine bacterium showing high SHMT activity, was selected based on screening bacterial strains and comparison of the activities of SHMTs. A glyA was isolated from the S. algae through thermal asymmetric interlaced PCR (TAIL-PCR) and it encoded a 417 amino acid polypeptide. The SaSHMT, encoded by the glyA, showed the optimal activity at 50°C and pH 7.0, and retained over 45% of its maximal activity after incubation at 40°C for 3h. The enzyme showed better stability under alkaline environment (pH 6.5-9.0) than Hyphomicrobium methylovorum GM2's SHMT (pH 6.0-7.5). The SaSHMT can produce 77.76mM of l-serine by enzymatic conversion, with the molecular conversion rate in catalyzing glycine to l-serine being 1.41-fold higher than that of Escherichia coli. Therefore, the SaSHMT has the potential for industrial applications due to its tolerance of alkaline environment and a relatively high enzymatic conversion rate.
authors: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
authors: Wei
authors: W
authors: Jiang
authors: Bingzhao
authors: B
authors: Xia
authors: Ziduo
authors: Z
authors: Liu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004789:Enzyme Activation; D015870:Gene Expression; D012696:Glycine Hydroxymethyltransferase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D012694:Serine / Q000096:biosynthesis*; D020592:Shewanella / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D012694:Serine; D012696:Glycine Hydroxymethyltransferase
keywords: Characterization; RP-HPLC; SHMT; TAIL-PCR; l-Serine enzymatic production