Title:Insights into Structure and Reaction Mechanism of β-Mannanases
Volume: 19
Issue: 1
Author(s): Kedar Sharma, Arun Dhillon and Arun Goyal*
Affiliation:
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam,India
Keywords:
β-mannanases, TIM barrel, crystal structure, reaction mechanism, degradation, GHs.
Abstract: β-mannanases have been shown to play an important role in various biological processes
such as the cell wall component degradation, defence signalling in plants, the mobilization of storage
reserves and in various industrial processes. To date, glycoside hydrolases (GHs) have been divided
into 135 families and 14 clans from A to N based upon their sequence, overall structural fold and function.
β -mannanases belong glycoside hydrolases and exist under four different glycoside hydrolase
families, GH5, GH26, GH113 and GH134. GH5 and GH26 are combined in clan GH-A. GH5 and
GH26 contain hydrolases which follow the retaining type reaction mechanism. Structural survey of β-
mannanases of GH5 and GH26, suggests that both families contain similar TIM barrel fold. In addition,
they also share common catalytic residues and their location in the structure. Despite these structural
similarities, a distinct difference lies between the substrate binding sub-sites which define substrate
specificity. This review summarizes the recent reports on the structure and function perspectives of β-
mannanases of GH5 and GH26 and highlights the similarities and differences between them.
