Processive or Nonprocessive Structure Function Relationship

Glycosyltransferase enzyme structure is divided into two domains: N-terminal domain A and C-terminal domain B. It has been noted that all glycosyltransferases

Figure 1 The catalytic mechanism of glycosyltransferases. (A) Inversion mechanism consisting of a single nucleophilic attack by the acceptor on the activated donor anomeric carbon. (B) Retention mechanism involving double nucleophilic substitution. The enzyme became transiently glycosylated and serves as the sugar donor in the subsequent steps [5]. The reaction goes through a proposed oxocarbenium transition state (middle left structure) [6]. Since aspartate and glutamate residues have been shown to be conserved and necessary for catalysis (see text), the general base and general acid functionalities shown are carboxylate groups. However, other functional groups could also perform these functions.

Figure 1 The catalytic mechanism of glycosyltransferases. (A) Inversion mechanism consisting of a single nucleophilic attack by the acceptor on the activated donor anomeric carbon. (B) Retention mechanism involving double nucleophilic substitution. The enzyme became transiently glycosylated and serves as the sugar donor in the subsequent steps [5]. The reaction goes through a proposed oxocarbenium transition state (middle left structure) [6]. Since aspartate and glutamate residues have been shown to be conserved and necessary for catalysis (see text), the general base and general acid functionalities shown are carboxylate groups. However, other functional groups could also perform these functions.

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