title: Molecular cloning and functional characterization of a novel decarboxylase from uncultured microorganisms.
abstract: The metagenomic library approach has been used successfully to isolate novel biocatalyst genes from uncultured microorganisms. We report the cloning of a novel decarboxylase gene by sequence-based screening of a plasmid metagenomic library constructed with DNA from alkaline polluted soils. The gene was named undec1 A and had an open reading frame of 1077 base pairs. It encoded a 359 amino acid polypeptide with a molecular mass of 38 kDa. The predicted protein had 58% similarity to a decarboxylase from Chlorobium phaeobacteroides BS1. The putative decarboxylase gene was subcloned into pETBlue-2 vector and overexpressed in Escherichia coli Tuner (DE3) pLac. The recombinant protein was purified to homogeneity. Functional characterization with liquid chromatography-mass spectrometry confirmed that the recombinant Undec1 A protein catalyzed the decarboxylation of L-cysteine to form cysteamine.
authors.affiliation: The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering, Guangxi University, 100 Daxue Road, Nanning, Guangxi 530004, People's Republic of China.
authors.forename: Chengjian
authors.initials: C
authors.lastname: Jiang
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
mesh_terms: D000595:Amino Acid Sequence; D002262:Carboxy-Lyases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018929:Cell Culture Techniques; D003001:Cloning, Molecular / Q000379:methods*; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D011994:Recombinant Proteins; D002262:Carboxy-Lyases