Cloning and Identification of Methionine Synthase Gene from Pichia pastoris

Autor: Lan Huang, Shao-Xiao Wang, Jun-Hui Chen, Xiang-Fu Wu, Shi-Ming Zhang, Dong-Yang Li
Rok vydání: 2005
Předmět:
Zdroj: Acta Biochimica et Biophysica Sinica. 37:371-378
ISSN: 1672-9145
DOI: 10.1111/j.1745-7270.2005.00054.x
Popis: Methionine synthase (MS) is grouped into two classes. Class One MS (MetH) and Class Two MS (MetE) share no homology and differ in their catalytic model. Based on the conserved sequences of metE genes from different organisms, a segment of the metE gene was first cloned from Pichia pastoris genomic DNA by PCR, and its 5' and 3' regions were further cloned by 5'- and 3'-rapid amplification of cDNA ends (RACE), respectively. The assembled sequence reveals an open reading frame encoding a polypeptide of 768 residues, and the deduced product shares 76% identity with MetE of Saccharomyces cerevisiae. P. pastoris methionine synthase (PpMetE) consists of two domains common to MetEs. The active site is located in the C-terminal domain, in which the residues involved in the interaction of zinc with substrates are conserved. Homologous expression of PpMetE in P. pastoris was achieved, and the heterolo- gous expression of PpMetE in the S. cerevisiae strain XJB3-1D that is MetE-defective restored the growth of the mutant on methionine-free minimal media. The gene sequence has been submitted to GenBank/ EMBL/DDBJ under accession No. AY601648.
Databáze: OpenAIRE