Crystal Structure and Characterization of the Glycoside Hydrolase Family 62 α-l-Arabinofuranosidase from Streptomyces coelicolor

Abstract

Background: Glycoside hydrolase family 62 ␣-L-arabinofuranosidases specifically release L-arabinose from arabinoxylan. Results: The crystal structure of glycoside hydrolase family 62 ␣-L-arabinofuranosidase from Streptomyces coelicolor was determined. Conclusion: L-Arabinose and xylohexaose complexed structures revealed the mechanism of substrate specificity of this enzyme. Significance: Efficient catalysis by glycoside hydrolase family 62 ␣-L-arabinofuranosidase requires its binding to terminal xylose sugars at the substrate-binding cleft.

GH62 arabinofuranosidases: Structure, function and applications

“…Araf substituents of Xylp (De La Mare et al, 2013;Maehara et al, 2014). This was seen also with WAX-HV as substrate for Streptomyces thermoviolaceus GH62 ABF (SthAbf62A-m2,3) that hydrolyzed -1,2 linked Araf after removal of 1,3 linked Araf from doubly substituted Xylp (Wang et al, 2014).…”

“…With regard to AXOS, the S. coelicolor ScAbf62A showed higher catalytic efficiency on XA 3 X (3 s -1 mM -1 ) and A 3 X (0.6 s -1 mM -1 ) compared to kcat of 0.3 s -1 for WAX (Maehara et al, 2014).…”

“…Notably the -anomer of Araf was bound at the active site in the crystal structure of ScAbf62A from S. coelicolor (Maehara et al, 2014).…”

“…3). The N-and C-terminal blades together forms a solar- (Kaur et al, 2014;Maehara et al, 2014;Siguier et al, 2014;Tonozuka et al, 2017;Wang et al, 2014) that occurs in nearly all -propeller fold proteins. This circular closure is important for protein stability and -propeller fold proteins in addition possess a disulfide bond that connects the N-and C-terminal strands of - (Jawad and Paoli, 2002;Neer and Smith, 1996) as in UmAbf62A (Cys10 and Cys278) (Siguier et al, 2014), ScAbf62A (Cys176 and Cys444) (Maehara et al, 2014) and SthAbf62A-m2,3…”

“…thermophilum GH62 ABF (StAbf62C) (PDB ID 4PVI); S. thermoviolaceus SthAbf62A-m2,3 (PDB ID 4O8N, 4O8O, 4O8P), U. maydis UmAbf62A (PDB ID 4N1I, 4N2R), P. anserina PaAbf62A (PDB ID 4N2Z, 4N4B), C. cinerea CcAbf62A (PDB ID 5B6S), and S. coelicolor ScAbf62A (PDB ID 3WMY, 3WMZ, 3WN0, 3WN1, 3WN2)) (Kaur et al, 2014;Maehara et al, 2014;Siguier et al, 2014;Tonozuka et al, 2017;Wang et al, 2014). These structures share a five--propeller fold catalytic domain where each blade has four twisted -strands radially orientated around a pseudo-5-fold axis (Fig.…”