PDBsum entry 1fxm

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protein links
Hydrolase PDB id
Protein chain
302 a.a.
Waters ×171
Superseded by: 1k6a
PDB id:
Name: Hydrolase
Title: Crystal structure of the thermoascus aurantiacus xylanase i
Structure: Xylanase i. Chain: a. Ec:
Source: Thermoascus aurantiacus. Fungus. Strain: imi 216529
1.14Å     R-factor:   0.114     R-free:   0.142
Authors: S.Teixeira,L.Lo Leggio,R.Pickersgill,C.Cardin
Key ref:
S.Teixeira et al. (2001). Anisotropic refinement of the structure of Thermoascus aurantiacus xylanase I. Acta Crystallogr D Biol Crystallogr, 57, 385-392. PubMed id: 11223515 DOI: 10.1107/S0907444900019089
26-Sep-00     Release date:   07-Mar-01    
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Protein chain
No UniProt id for this chain
Struc: 302 a.a.
Key:    Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.  - Endo-1,4-beta-xylanase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Endohydrolysis of 1,4-beta-D-xylosidic linkages in xylans.


DOI no: 10.1107/S0907444900019089 Acta Crystallogr D Biol Crystallogr 57:385-392 (2001)
PubMed id: 11223515  
Anisotropic refinement of the structure of Thermoascus aurantiacus xylanase I.
S.Teixeira, L.Lo Leggio, R.Pickersgill, C.Cardin.
The isotropic crystallographic model of the structure of xylanase I from Thermoascus aurantiacus (TAXI) has now been refined anisotropically at 1.14 A resolution to a standard residual of R = 11.1% for all data. TAXI is amongst the five largest proteins deposited in the Protein Data Bank to have been refined with anisotropic displacement parameters (ADPs) at this level of resolution. The anisotropy analysis revealed a more isotropic distribution of anisotropy than usually observed previously. Adding ADPs resulted in high-quality electron-density maps which revealed discrepancies from the previously suggested primary sequences for this enzyme. Side-chain conformational disorder was modelled for 16 residues, including Trp275, a bulky residue at the active site. An unrestrained refinement was consistent with the protonation of the catalytic acid/base glutamate and the deprotonation of the nucleophile glutamate, as required for catalysis. The thermal stability of TAXI is reinterpreted in the light of the new refined model.
  Selected figure(s)  
Figure 3.
Figure 3 In the top-left corner a side view of the ( )[8] TIM-barrel fold of TAXI can be seen. A zoom on the active site shows the side chains of some selected residues (blue), illustrating the environment around the active-site glutamates (red). The alternate conformations of Trp275 are coloured in green. The top right corner shows a top view along the barrel.
Figure 5.
Figure 5 Progress of the refinement. The residual R factor is defined as R = |F[o]| - |F[c]| / |F[o]|.
  The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2001, 57, 385-392) copyright 2001.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
12761390 J.Le Nours, C.Ryttersgaard, L.Lo Leggio, P.R.Østergaard, T.V.Borchert, L.L.Christensen, and S.Larsen (2003).
Structure of two fungal beta-1,4-galactanases: searching for the basis for temperature and pH optimum.
  Protein Sci, 12, 1195-1204.
PDB codes: 1hjq 1hjs 1hju
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