title: Cloning, sequence analysis and expression of gene alyVI encoding alginate lyase from marine bacterium Vibrio sp. QY101.
abstract: The gene (alyVI) encoding an alginate lyase of marine bacterium Vibrio sp. QY101, which was isolated from a decaying thallus of Laminaria, was cloned using a strategy of combined degenerate PCR and long range-inverse PCR (LR-IPCR), then sequenced and expressed in Escherichia coli. Gene alyVI was composed of a 1014 bp open reading frame (ORF) encoding 338 amino acid residues. The calculated molecular mass of alyVI product is 38.4 kDa, but a signal peptide is cleaved off, leaving a mature protein of 34 kDa. AlyVI was purified from culture supernatants to electrophoretic homogeneity using affinity chromatography. AlyVI was most active at pH 7.5 and 40 degrees C in the presence of 1 mM ZnCl2. A nine-amino-acid consensus region (YXRESLREM), which was only found in polyguluronate lyases, was also observed in the amino-terminal region of AlyVI. However, AlyVI could degrade both M block and G block. These results indicate that a novel alginate lyase-encoding gene has been cloned.
authors.affiliation: Key Laboratory of Marine Drugs, Ocean University of China, Ministry of Education, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Han
authors.forename: Qian-Hong
authors.initials: QH
authors.lastname: Gong
authors.forename: Kai
authors.initials: K
authors.lastname: Song
authors.forename: Jing-Bao
authors.initials: JB
authors.lastname: Li
authors.forename: Wen-Gong
authors.initials: WG
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D004926:Escherichia coli / Q000378:metabolism; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007795:Laminaria / Q000382:microbiology*; D008969:Molecular Sequence Data; D010140:Pacific Ocean; D010957:Plasmids / Q000235:genetics; D011133:Polysaccharide-Lyases / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014169:Transformation, Bacterial; D014733:Vibrio / Q000235:genetics*
chemical_list: D017931:DNA Primers; D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase