5lu3

The Structure of Spirochaeta thermophila CBM64The Structure of Spirochaeta thermophila CBM64

Structural highlights 5lu3 is a 1 chain structure with sequence from Spirochaeta thermophila DSM 6578. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.5Å Ligands: , , , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function G0GE26_SPITZ Publication Abstract from PubMed Deconstruction of cellulose, the most abundant plant cell wall polysaccharide, requires the cooperative activity of a large repertoire of microbial enzymes. Modular cellulases contain non-catalytic type A Carbohydrate-Binding Modules (CBMs) that specifically bind to the crystalline regions of cellulose, thus promoting enzyme efficacy through proximity and targeting effects. Although type A CBMs play a critical role in cellulose recycling, their mechanism of action remains poorly understood. Here we produced a library of recombinant CBMs representative of the known diversity of type A modules. The binding properties of 40 CBMs, in fusion with an N-terminal green fluorescence protein (GFP) domain, revealed that type A CBMs possess the ability to recognize different crystalline forms of cellulose and chitin over a wide range of temperatures, pHs and ionic strengths. A Spirochaeta thermophila CBM64, in particular, displayed plasticity in its capacity to bind both crystalline and soluble carbohydrates under a wide range of extreme conditions. The structure of S. thermophila StCBM64C revealed an untwisted, flat, carbohydrate-binding interface comprising the side chains of four tryptophan residues in a coplanar linear arrangement. Significantly, two highly conserved asparagine side chains, each one located between two tryptophan residues, are critical to insoluble and soluble glucan recognition but not to bind xyloglucan. Thus, CBM64 compact structure and its extended and versatile ligand interacting platform illustrates how type A CBMs target their appended plant cell wall degrading enzymes to a diversity of recalcitrant carbohydrates under a wide range of environmental conditions. Stability and ligand promiscuity of type A carbohydrate-binding modules are illustrated by the structure of Spirochaeta thermophila StCBM64C.,Pires VM, Pereira PM, Bras JL, Correia M, Cardoso V, Bule P, Alves VD, Najmudin S, Venditto I, Ferreira LM, Romao MJ, Carvalho AL, Fontes CM, Prazeres DM J Biol Chem. 2017 Feb 8. pii: jbc.M116.767541. doi: 10.1074/jbc.M116.767541. PMID:28179427 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 5lu3, resolution 1.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image