Abstract
Levansucrase is responsible for levan formation during sucrose fermentation of Zymomonas mobilis, and this decreases the efficiency of ethanol production. As thiol modifying agents decrease levan formation, a role for cysteine residues in levansucrase activity has been examined using derivatives of Z. mobilis levansucrase that carry serine substitutions of cysteine at positions 121, 151 or 244. These substitutions abolished the levan forming activity of levansucrase whilst only halving its activity in sucrose hydrolysis. Thus, polymerase and hydrolase activities of Z. mobilis levansucrase are separate and have different requirements for the enzyme's cysteine residues.
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Bradford MM (1976) A rapid and sensitive method for the quantitation of microgramquantities of protein utilizing the principle of protein-dye binding. Anal. Biochem. 72: 248–254.
Chambert R, Petit-Glatron MF (1991) Polymerase and hydrolase activities of Bacillus subtilis levansucrase can be separately modulated by site-directed mutagenesis. Biochem. J. 279: 35–41.
Gunasekaran P, Mukundan G, Kannan R, Velmurugan S, Ait-Abdelkadhar N, Alvarez-Macarie E, Baratti J (1995) The sacB and sacC genes encoding levansucrase and sucrase from a gene cluster in Zymomonas mobilis. Biotechnol. Lett. 17: 635–642.
Kannan TR, Mukundan AG, Gunasekaran P (1993) Fermentation characteristics of levansucrase mutants of Zymomonas mobilis. Ferm. Bioeng. 75, 265–270.
O'Mullan P, Szakacs-Dobozi M, Eveleigh DE (1991) Identification of saccharolytic enzymes of Zymomonas mobilis CP4. Biotechnol. Lett. 13: 137–142.
Sangiliyandi G, Gunasekaran P (1998) A simple method for purification of thermostable levansucrase of Zymomonas mobilis from a recombinant Escherichia coli. J. Microbiol. Meth. 33: 153–156.
Sangiliyandi G, Gunasekaran P (2001) Polymerase and hydrolase activities of Zymomonas mobilis levansucrase separately modulated by in vitro mutagenesis and elevated temperature. Process Biochem. 36: 543–548.
Sangiliyandi G, Kannan TR, Chandraraj K, Gunasekaran P (1999) Elevated temperature and chemical modification selectively abolishes levan forming activity of levansucrase of Zymomonas mobilis. Biotechnol. Lett. 21: 179–182.
Studier FW, Moffatt BA (1986) Use of bacteriophage of T7 RNA polymerse to direct selective high level expression of cloned genes. J. Mol. Biol. 189: 113–130.
Viikari L (1984) Formation of levan and sorbital from sucrose by Zymomonas mobilis. Appl. Microbiol. Biotechnol. 19: 252–255.
Yanase H, Maeda M, Hagiwara E, Yagi H, Taniguchi K, Okamoto K (2002) Identification of functionally important amino acid residues in Zymomonas mobilis levansucrase. J. Biochem. 132: 565–572.
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Senthilkumar, V., Busby, S.J. & Gunasekaran, P. Serine substitution for cysteine residues in levansucrase selectively abolishes levan forming activity. Biotechnology Letters 25, 1653–1656 (2003). https://doi.org/10.1023/A:1025650928313
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DOI: https://doi.org/10.1023/A:1025650928313