title: C-Terminal proline-rich sequence broadens the optimal temperature and pH ranges of recombinant xylanase from Geobacillus thermodenitrificans C5.
abstract: Efficient utilization of hemicellulose entails high catalytic capacity containing xylanases. In this study, proline rich sequence was fused together with a C-terminal of xylanase gene from Geobacillus thermodenitrificans C5 and designated as GthC5ProXyl. Both GthC5Xyl and GthC5ProXyl were expressed in Escherichia coli BL21 host in order to determine effect of this modification. The C-terminal oligopeptide had noteworthy effects and instantaneously extended the optimal temperature and pH ranges and progressed the specific activity of GthC5Xyl. Compared with GthC5Xyl, GthC5ProXyl revealed improved specific activity, a higher temperature (70°C versus 60°C) and pH (8 versus 6) optimum, with broad ranges of temperature and pH (60-80°C and 6.0-9.0 versus 40-60°C and 5.0-8.0, respectively). The modified enzyme retained more than 80% activity after incubating in xylan for 3h at 80°C as compared to wild -type with only 45% residual activity. Our study demonstrated that proper introduction of proline residues on C-terminal surface of xylanase family might be very effective in improvement of enzyme thermostability. Moreover, this study reveals an engineering strategy to improve the catalytic performance of enzymes.
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Irfan
authors.affiliation: Department of Molecular Biology and Genetic, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Halil Ibrahim
authors.initials: HI
authors.lastname: Guler
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Aysegul
authors.initials: A
authors.lastname: Ozer
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon, Turkey.
authors.forename: Merve Tuncel
authors.initials: MT
authors.lastname: Sapmaz
authors.affiliation: Department of Biology, Faculty of Sciences, Karadeniz Technical University, 61080 Trabzon, Turkey. Electronic address: belduz@ktu.edu.tr.
authors.forename: Ali Osman
authors.initials: AO
authors.lastname: Belduz
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan.
authors.forename: Fariha
authors.initials: F
authors.lastname: Hasan
authors.affiliation: Department of Microbiology, Faculty of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan.
authors.forename: Aamer Ali
authors.initials: AA
authors.lastname: Shah
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D043364:Endo-1,4-beta Xylanases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D005798:Genes, Bacterial; D056506:Geobacillus / Q000201:enzymology* / Q000235:genetics; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011134:Polysaccharides / Q000378:metabolism; D011392:Proline / Q000737:chemistry; D015202:Protein Engineering; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D014990:Xylans / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011134:Polysaccharides; D011994:Recombinant Proteins; D014990:Xylans; C007916:hemicellulose; D011392:Proline; D043364:Endo-1,4-beta Xylanases
keywords: Characterization; Geobacillus thermodinitrificans C5 recombinant xylanase (GthC5Xyl); Proline tagged xylanase (GthC5ProXyl); Thermostability; Xylanase