title: Emerging role of N- and C-terminal interactions in stabilizing (β/α)8 fold with special emphasis on Family 10 xylanases.
abstract: Xylanases belong to an important class of industrial enzymes. Various xylanases have been purified and characterized from a plethora of organisms including bacteria, marine algae, plants, protozoans, insects, snails and crustaceans. Depending on the source, the enzymatic activity of xylanases varies considerably under various physico-chemical conditions such as temperature, pH, high salt and in the presence of proteases. Family 10 or glycosyl hydrolase 10 (GH10) xylanases are one of the well characterized and thoroughly studied classes of industrial enzymes. The TIM-barrel fold structure which is ubiquitous in nature is one of the characteristics of family 10 xylanases. Family 10 xylanases have been used as a "model system" due to their TIM-barrel fold to dissect and understand protein stability under various conditions. A better understanding of structure-stability-function relationships of family 10 xylanases allows one to apply these governing molecular rules to engineer other TIM-barrel fold proteins to improve their stability and retain function(s) under adverse conditions. In this review, we discuss the implications of N-and C-terminal interactions, observed in family 10 xylanases on protein stability under extreme conditions. The role of metal binding and aromatic clusters in protein stability is also discussed. Studying and understanding family 10 xylanase structure and function, can contribute to our protein engineering knowledge.
authors.affiliation: Molecular Pathology Lab, International Centre for Genetic Engineering and Biotechnology, AREA Science Park, Padriciano 99, 34149, Trieste, Italy.
authors.forename: Amit
authors.initials: A
authors.lastname: Bhardwaj
authors.affiliation: Department of Physics, Indian Institute of Science, Bangalore, India.
authors.forename: Pranjal
authors.initials: P
authors.lastname: Mahanta
authors.affiliation: Department of Physics, Indian Institute of Science, Bangalore, India.
authors.forename: Suryanarayanarao
authors.initials: S
authors.lastname: Ramakumar
authors.affiliation: National Institute of Cholera and Enteric diseases, Kolkata, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Ghosh
authors.affiliation: Plant Transformation Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi - 110067, India.
authors.forename: Sadhu
authors.initials: S
authors.lastname: Leelavathi
authors.affiliation: Plant Transformation Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi - 110067, India.
authors.forename: Vanga Siva
authors.initials: VS
authors.lastname: Reddy
keywords: Aromatic clusters; Family 10 Xylanase; Metal binding; Protein engineering; TIM barrel fold; Thermal stability