4IPM

Crystal structure of a GH7 family cellobiohydrolase from Limnoria quadripunctata in complex with thiocellobiose

4IPM の概要

• エントリーDOI: 10.2210/pdb4ipm/pdb
• 関連するPDBエントリー: 4GWA 4HAP 4HAQ
• 関連するBIRD辞書のPRD_ID: PRD_900034
• 分子名称: GH7 family protein, beta-D-glucopyranose-(1-4)-4-thio-beta-D-glucopyranose, CALCIUM ION, ... (5 entities in total)
• 機能のキーワード: thiocellobiose, cellobiohydrolase, hydrolase
• 由来する生物種: Limnoria quadripunctata
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 46993.43

構造登録者

McGeehan, J.E.,Martin, R.N.A.,Streeter, S.D.,Cragg, S.M.,Guille, M.J.,Schnorr, K.M.,Kern, M.,Bruce, N.C.,McQueen-Mason, S.J. (登録日: 2013-01-10, 公開日: 2013-06-12, 最終更新日: 2024-10-16)

主引用文献

Kern, M.,McGeehan, J.E.,Streeter, S.D.,Martin, R.N.,Besser, K.,Elias, L.,Eborall, W.,Malyon, G.P.,Payne, C.M.,Himmel, M.E.,Schnorr, K.,Beckham, G.T.,Cragg, S.M.,Bruce, N.C.,McQueen-Mason, S.J.
Structural characterization of a unique marine animal family 7 cellobiohydrolase suggests a mechanism of cellulase salt tolerance.
Proc.Natl.Acad.Sci.USA, 110:10189-10194, 2013

PubMed Abstract: Nature uses a diversity of glycoside hydrolase (GH) enzymes to convert polysaccharides to sugars. As lignocellulosic biomass deconstruction for biofuel production remains costly, natural GH diversity offers a starting point for developing industrial enzymes, and fungal GH family 7 (GH7) cellobiohydrolases, in particular, provide significant hydrolytic potential in industrial mixtures. Recently, GH7 enzymes have been found in other kingdoms of life besides fungi, including in animals and protists. Here, we describe the in vivo spatial expression distribution, properties, and structure of a unique endogenous GH7 cellulase from an animal, the marine wood borer Limnoria quadripunctata (LqCel7B). RT-quantitative PCR and Western blot studies show that LqCel7B is expressed in the hepatopancreas and secreted into the gut for wood degradation. We produced recombinant LqCel7B, with which we demonstrate that LqCel7B is a cellobiohydrolase and obtained four high-resolution crystal structures. Based on a crystallographic and computational comparison of LqCel7B to the well-characterized Hypocrea jecorina GH7 cellobiohydrolase, LqCel7B exhibits an extended substrate-binding motif at the tunnel entrance, which may aid in substrate acquisition and processivity. Interestingly, LqCel7B exhibits striking surface charges relative to fungal GH7 enzymes, which likely results from evolution in marine environments. We demonstrate that LqCel7B stability and activity remain unchanged, or increase at high salt concentration, and that the L. quadripunctata GH mixture generally contains cellulolytic enzymes with highly acidic surface charge compared with enzymes derived from terrestrial microbes. Overall, this study suggests that marine cellulases offer significant potential for utilization in high-solids industrial biomass conversion processes.

PubMed: 23733951
DOI: 10.1073/pnas.1301502110

実験手法

X-RAY DIFFRACTION (1.14 Å)