Research Data from Beihang University Update Understanding of Transferases (Structural basis of a mutant Y195I alpha-cyclodextrin glycosyltransferase with switched product specificity from alpha-cyclodextrin to beta-/gamma-cyclodextrin)
By a News Reporter-Staff News Editor at Biotech Week -- Current study results on Enzymes and Coenzymes have been published. According to news reporting from Beijing, People's Republic of China, by NewsRx journalists, research stated, "Cyclodextrin glycosyltransferase (EC 22.214.171.124) (CGTase) is an extracellular bacterial enzyme which has the unique capability of forming cyclodextrins from starch. Our previous investigation revealed that a mutant Y195I alpha-CGTase drastically altered the cyclodextrin specificity by switching toward the synthesis of both beta- and gamma-CDs (Xie et al., 2013a,b)."
The news correspondents obtained a quote from the research from Beihang University, "In this study, we determined one X-ray structure of the mutant Y195I alpha-CGTase at 2.3 angstrom. The overall structure was similar to that of the typical beta-CGTase from Bacillus circulans 251, with minor difference in flexible domains since they showed about 70% homogeneity of amino acid sequences. The central site with isoleucine tended to be more flexible than tyrosine thus made the sugar chain, during the cyclization process, form a larger cyclodextrin like beta- and gamma-CDs surrounding the central site instead of alpha-CD. Superposition of the structure of Y195I alpha-CGTase with those of beta-CGTase and gamma-CGTase showed that residues Lys232, Lys89 and Arg177 at subsites +2, -3 and -7 could form smaller substrate binding cavity. In summary, the crystal structure revealed that moderate increase of mobility of the central site resulted in the switched product specificity from alpha-CD to beta- and gamma-CDs of the mutant Y195I alpha-CGTase."
According to the news reporters, the research concluded: "The space differences alongside the active domain may be another factor that impacts the product specificity of the CGTase."
For more information on this research see: Structural basis of a mutant Y195I alpha-cyclodextrin glycosyltransferase with switched product specificity from alpha-cyclodextrin to beta-/gamma-cyclodextrin. Journal of Biotechnology, 2014;182():92-96. Journal of Biotechnology can be contacted at: Elsevier Science Bv, PO Box 211, 1000 Ae Amsterdam, Netherlands. (Elsevier - www.elsevier.com; Journal of Biotechnology - www.elsevier.com/wps/product/cws_home/505515)
Our news journalists report that additional information may be obtained by contacting T. Xie, Beihang Univ BUAA, Sch Biol Sci & Med Engn, Key Lab Biomechan & Mechanobiol, Minist Educ, Beijing 100191, People's Republic of China. Additional authors for this research include Y.J. Hou, D.F. Li, Y. Yue, S.J. Qian and Y.P. Chao (see also Enzymes and Coenzymes).
Keywords for this news article include: Asia, Beijing, Glycosyltransferases, Enzymes and Coenzymes, People's Republic of China
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