Characterization and Sequence Analysis of a Lily Isolate of Cucumber mosaic virus from Lilium tsingtauense
Triclosan Resistance in a Bacterial Fish Pathogen, Aeromonas salmonicida subsp. salmonicida, is Mediated by an Enoyl Reductase, FabV
Biocatalysis and Fermentation Technology : Secretory Expression, Functional Characterization, and Molecular Genetic Analysis of Novel Halo-Solvent-Tolerant Protease from Bacillus gibsonii
Cloning, High-Level Expression, Purification, and Properties of a Novel Endo-β-1,4-Mannanase from Bacillus subtilis G1 in Pichia pastoris
S5-1 : Fungal endophytes isolated from various plants of korea : distribution, diversity, and characterization
The α-galactosidase-coding gene agaAJB13 was cloned from Sphingomonas sp. JB13 showing 16S rDNA (1,343 bp) identities of ≤97.2% with other identified Sphingomonas strains. agaAJB13 (2,217 bp; 64.9% GC content) encodes a 738-residue polypeptide (AgaAJB13) with a calculated mass of 82.3 kDa. AgaAJB13 showed the highest identity of 61.4% with the putative glycosyl hydrolase family 36 α-galactosidase from Granulicella mallensis MP5ACTX8 (EFI56085). AgaAJB13 also showed <37% identities with reported protease-resistant or Sphingomonas α-galactosidases. A sequence analysis revealed different catalytic motifs between reported Sphingomonas α-galactosidases (KXD and RXXXD) and AgaAJB13 (KWD and SDXXDXXXR). Recombinant AgaAJB13 (rAgaAJB13) was expressed in Escherichia coli BL21 (DE3). The purified rAgaAJB13 was characterized using p-nitrophenyl-α-D-galactopyranoside as the substrate and showed an apparent optimum at pH 5.0 and 60oC and strong resistance to trypsin and proteinase K digestion. Compared with reported proteaseresistant α-galactosidases showing thermolability at 50oC or 60oC and specific activities of <71 U/mg with or without protease treatments, rAgaAJB13 exhibited a better thermal stability (half-life of >60 min at 60oC) and higher specific activities (225.0-256.5 U/mg). These sequence and enzymatic properties suggest AgaAJB13 is the first identified and characterized Sphingomonas α-galactosidase, and shows novel protease resistance with a potential value for basic research and industrial applications.