Altered sugar donor specificity and catalytic activity of pteridine glycosyltransferases by domain swapping or site-directed mutagenesis

• Published in: BMB reports Vol. 46; no. 1; pp. 37 - 40
• Main Authors: Kim, H.L., Inje University, Kimhae, Republic of korea, Kim, A.H., Inje University, Kimhae, Republic of korea, Park, M.B., Inje University, Kimhae, Republic of korea, Lee, S.W., College of Medicine, Republic of Korea, Park, Y.S., Inje University, Kimhae, Republic of korea
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society for Biochemistry and Molecular Biology 01.01.2013; 생화학분자생물학회
• Subjects: Amino Acid Sequence; Domain swapping; Domain swapping,Pteridine glycosyltransferase,Substrate specificity,Tetrahydrobiopterin; Glycosyltransferases - chemistry; Glycosyltransferases - genetics; Glycosyltransferases - metabolism; Molecular Sequence Data; MUTACION; Mutagenesis, Site-Directed; MUTATION; Protein Structure, Tertiary; Pteridine glycosyltransferase; Recombinant Proteins - biosynthesis; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Sequence Homology, Amino Acid; Site-directed mutagenesis; Substrate Specificity; Tetrahydrobiopterin; 화학
• ISSN: 1976-6696; 1976-670X
• DOI: 10.5483/BMBRep.2013.46.1.147

CY-007 and CY-049 pteridine glycosyltransferases (PGTs) that differ in sugar donor specificity to catalyze either glucose or xylose transfer to tetrahydrobiopterin were studied here to uncover the structural determinants necessary for the specificity. The importance of the C-terminal domain and its residues 218 and 258 that are different between the two PGTs was assessed via structure-guided domain swapping or single and dual amino acid substitutions. Catalytic activity and selectivity were altered in all the mutants (2 chimeric and 6 substitution) to accept both UDP-glucose and UDP-xylose. In addition, the wild type activities were improved 1.6-4.2 fold in 4 substitution mutants and activity was observed towards another substrate UDP-Nacetylglucosamine in all the substitution mutants from CY-007 PGT. The results strongly support essential role of the C-terminal domain and the two residues for catalysis as well as sugar donor specificity, bringing insight into the structural features of the PGTs.