Abstract
The GH94 glycoside hydrolase cellodextrin phosphorylase (CDP, EC 2.4.1.49) produces cellodextrin oligomers from short β-1→4-glucans and α-D-glucose 1-phosphate. Compared to cellobiose phosphorylase (CBP), which produces cellobiose from glucose and α-D-glucose 1-phosphate, CDP is biochemically less well characterised. Herein, we investigate the donor and acceptor substrate specificity of recombinant CDP from Ruminiclostridium thermocellum and we isolate and characterise a glucosamine addition product to the cellobiose acceptor with the non-natural donor α-D-glucosamine 1-phosphate. In addition, we report the first X-ray crystal structure of CDP, along with comparison to the available structures from CBPs and other closely related enzymes, which contributes to understanding of the key structural features necessary to discriminate between monosaccharide (CBP) and oligosaccharide (CDP) acceptor substrates.
Highlights
We report the first X-ray crystal structure of cellodextrin phosphorylase (CDP), along with comparison to the available structures from cellobiose phosphorylase (CBP) and other closely related enzymes, which contributes to understanding of the key structural features necessary to discriminate between monosaccharide (CBP) and oligosaccharide (CDP) acceptor substrates
CDP (EC 2.4.1.49) belongs to the glycoside hydrolase family GH94 in the Carbohydrate Active Enzyme (CAZY) database (URL: http://www.cazy.org/) [25], along with cellobiose phosphorylase (CBP), which has been extensively characterised from a variety of sources [26e29]
Less comprehensive studies have been conducted on CDP activity and specificity; it has been used to synthesise a variety of cellulose derivatives, assessing its permissiveness toward acceptors (Table S1), but less information is available about its donor specificity [30,31] (Table S2) and no X-ray crystal structure is available for this enzyme
Summary
Hiraishi et al described the synthesis of crystalline celluloselike material with an average of ~ DP 9 using high concentration of glucose as CDP acceptor [24]. CDP (EC 2.4.1.49) belongs to the glycoside hydrolase family GH94 in the Carbohydrate Active Enzyme (CAZY) database (URL: http://www.cazy.org/) [25], along with cellobiose phosphorylase (CBP), which has been extensively characterised from a variety of sources [26e29]. Less comprehensive studies have been conducted on CDP activity and specificity; it has been used to synthesise a variety of cellulose derivatives, assessing its permissiveness toward acceptors (Table S1), but less information is available about its donor specificity [30,31] (Table S2) and no X-ray crystal structure is available for this enzyme. We report studies that investigate the donor and acceptor specificity of recombinant R. thermocellum CDP.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
