Cloning And Partial Characterization Of An Extracellular Dextransucrase Coding Region (Dsr-V) From Leuconostoc Citreum M-3

The dextransucrase enzymes synthesize dextran, a glucose polymer with broad industrial applications, making the search for new dextransucrases of great interest. The work described aimed at the partial characterizing of a recombinant dextransucrase enzyme from Leuconostoc citreum M-3. From the genomic DNA of strain M-3, an amplicon containing a coding region of a dextransucrase called DSRV was isolated, and deposited in the GenBankTM (Accession number: KF724950). The amino acid sequence alignment of DSR-V with other dextransucrases demonstrated that it shares a 94% identity with the DSR-D of L. mesenteroides Lcc4 and the DSR-S of L. mesenteroides NRRL B-512F. The DSR-V was cloned and expressed in Escherichia coli JM109 facilitating the formation and detection of DSR-V specific dextran. The SDS-PAGE soluble fraction zymography of E. coli DSR-V and the C-13-NMR spectra of dextran polymers synthesized by this clone confirm that L. citreum M-3 dsrV gene codes for a different dextransucrase synthesizing linear dextrans with mainly alpha(1-6) linkages.