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452 a.a.
Key reference
DOI no: 10.1021/bi050779v Biochemistry 44:12700-12708 (2005) PubMed id: 16171384
The structure and characterization of a modular endo-beta-1,4-mannanase from Cellulomonas fimi. J.Le Nours, L.Anderson, D.Stoll, H.Stålbrand, L.Lo Leggio. ABSTRACT
The endo-beta-1,4-mannanase from the soil bacterium Cellulomonas fimi is a modular plant cell wall degrading enzyme involved in the hydrolysis of the backbone of mannan, one of the most abundant polysaccharides of the hemicellulosic network in the plant cell wall. The crystal structure of a recombinant truncated endo-beta-1,4-mannanase from C. fimi (CfMan26A-50K) was determined by X-ray crystallography to 2.25 A resolution using the molecular replacement technique. The overall structure of the enzyme consists of a core (beta/alpha)8-barrel catalytic module characteristic of clan GH-A, connected via a linker to an immunoglobulin-like module of unknown function. A complex with the oligosaccharide mannotriose to 2.9 A resolution has also been obtained. Both the native structure and the complex show a cacodylate ion bound at the -1 subsite, while subsites -2, -3, and -4 are occupied by mannotriose in the complex. Enzyme kinetic analysis and the analysis of hydrolysis products from manno-oligosaccharides and mannopentitol suggest five important active-site cleft subsites. CfMan26A-50K has a high affinity -3 subsite with Phe325 as an aromatic platform, which explains the mannose releasing property of the enzyme. Structural differences with the homologous Cellvibrio japonicus beta-1,4-mannanase (CjMan26A) at the -2 and -3 subsites may explain the poor performance of CfMan26A mutants as "glycosynthases".
Literature references that cite this PDB file's key reference
PubMed id Reference
19543714 H.Schagerlöf, C.Nilsson, L.Gorton, F.Tjerneld, H.Stålbrand, and A.Cohen (2009).
Use of 18O water and ESI-MS detection in subsite characterisation and investigation of the hydrolytic action of an endoglucanase.Anal Bioanal Chem, 394, 1977-1984.
18820840 P.Yang, Y.Li, Y.Wang, K.Meng, H.Luo, T.Yuan, Y.Bai, Z.Zhan, and B.Yao (2009).
A novel beta-mannanase with high specific activity from Bacillus circulans CGMCC1554: gene cloning, expression and enzymatic characterization.Appl Biochem Biotechnol, 159, 85-94.
18755688 Y.Zhang, J.Ju, H.Peng, F.Gao, C.Zhou, Y.Zeng, Y.Xue, Y.Li, B.Henrissat, G.F.Gao, and Y.Ma (2008).
Biochemical and Structural Characterization of the Intracellular Mannanase AaManA of Alicyclobacillus acidocaldarius Reveals a Novel Glycoside Hydrolase Family Belonging to Clan GH-A.J Biol Chem, 283, 31551-31558.
PDB code: 3civ
17287210 L.E.Tailford, V.A.Money, N.L.Smith, C.Dumon, G.J.Davies, and H.J.Gilbert (2007).
Mannose foraging by Bacteroides thetaiotaomicron: structure and specificity of the beta-mannosidase, BtMan2A.J Biol Chem, 282, 11291-11299.
PDB code: 2je8 The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.
