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PDBsum entry 2f8q

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protein metals Protein-protein interface(s) links
Hydrolase PDB id
2f8q
Jmol
Contents
Protein chains
353 a.a. *
Metals
_MG ×2
Waters ×752
* Residue conservation analysis
PDB id:
2f8q
Name: Hydrolase
Title: An alkali thermostable f/10 xylanase from alkalophilic bacil ng-27
Structure: Alkaline thermostable endoxylanase. Chain: a, b. Ec: 3.2.1.8
Source: Bacillus sp. Ng-27. Organism_taxid: 65673
Resolution:
2.20Å     R-factor:   0.197     R-free:   0.235
Authors: S.Ramakumar,K.Manikandan,A.Bhardwaj,A.Ghosh,V.S.Reddy
Key ref: K.Manikandan et al. (2006). Crystal structures of native and xylosaccharide-bound alkali thermostable xylanase from an alkalophilic Bacillus sp. NG-27: structural insights into alkalophilicity and implications for adaptation to polyextreme conditions. Protein Sci, 15, 1951-1960. PubMed id: 16823036 DOI: 10.1110/ps.062220206
Date:
03-Dec-05     Release date:   26-Sep-06    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chains
Pfam   ArchSchema ?
O30700  (O30700_9BACI) -  Beta-xylanase
Seq:
Struc:
405 a.a.
353 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.3.2.1.8  - Endo-1,4-beta-xylanase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: Endohydrolysis of 1,4-beta-D-xylosidic linkages in xylans.
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     metabolic process   4 terms 
  Biochemical function     hydrolase activity     5 terms  

 

 
DOI no: 10.1110/ps.062220206 Protein Sci 15:1951-1960 (2006)
PubMed id: 16823036  
 
 
Crystal structures of native and xylosaccharide-bound alkali thermostable xylanase from an alkalophilic Bacillus sp. NG-27: structural insights into alkalophilicity and implications for adaptation to polyextreme conditions.
K.Manikandan, A.Bhardwaj, N.Gupta, N.K.Lokanath, A.Ghosh, V.S.Reddy, S.Ramakumar.
 
  ABSTRACT  
 
Crystal structures are known for several glycosyl hydrolase family 10 (GH10) xylanases. However, none of them is from an alkalophilic organism that can grow in alkaline conditions. We have determined the crystal structures at 2.2 Angstroms of a GH10 extracellular endoxylanase (BSX) from an alkalophilic Bacillus sp. NG-27, for the native and the complex enzyme with xylosaccharides. The industrially important enzyme is optimally active and stable at 343 K and at a pH of 8.4. Comparison of the structure of BSX with those of other thermostable GH10 xylanases optimally active at acidic or close to neutral pH showed that the solvent-exposed acidic amino acids, Asp and Glu, are markedly enhanced in BSX, while solvent-exposed Asn was noticeably depleted. The BSX crystal structure when compared with putative three-dimensional homology models of other extracellular alkalophilic GH10 xylanases from alkalophilic organisms suggests that a protein surface rich in acidic residues may be an important feature common to these alkali thermostable enzymes. A comparison of the surface features of BSX and of halophilic proteins allowed us to predict the activity of BSX at high salt concentrations, which we verified through experiments. This offered us important lessons in the polyextremophilicity of proteins, where understanding the structural features of a protein stable in one set of extreme conditions provided clues about the activity of the protein in other extreme conditions. The work brings to the fore the role of the nature and composition of solvent-exposed residues in the adaptation of enzymes to polyextreme conditions, as in BSX.
 

Literature references that cite this PDB file's key reference

  PubMed id Reference
21436878 Y.Zhao, Y.Zhang, Y.Cao, J.Qi, L.Mao, Y.Xue, F.Gao, H.Peng, X.Wang, G.F.Gao, and Y.Ma (2011).
Structural analysis of alkaline β-mannanase from alkaliphilic Bacillus sp. N16-5: implications for adaptation to alkaline conditions.
  PLoS One, 6, e14608.  
20596542 A.Bhardwaj, S.Leelavathi, S.Mazumdar-Leighton, A.Ghosh, S.Ramakumar, and V.S.Reddy (2010).
The critical role of N- and C-terminal contact in protein stability and folding of a family 10 xylanase under extreme conditions.
  PLoS One, 5, e11347.  
20730475 G.Zhang, L.Mao, Y.Zhao, Y.Xue, and Y.Ma (2010).
Characterization of a thermostable xylanase from an alkaliphilic Bacillus sp.
  Biotechnol Lett, 32, 1915-1920.  
18725971 A.Bharadwaj, S.Leelavathi, S.Mazumdar-Leighton, A.Ghosh, S.Ramakumar, and V.S.Reddy (2008).
The critical role of partially exposed N-terminal valine residue in stabilizing GH10 xylanase from Bacillus sp.NG-27 under poly-extreme conditions.
  PLoS ONE, 3, e3063.  
18275861 L.P.Wackett (2008).
Biomass to fuels via microbial transformations.
  Curr Opin Chem Biol, 12, 187-193.  
17642511 V.Solomon, A.Teplitsky, S.Shulami, G.Zolotnitsky, Y.Shoham, and G.Shoham (2007).
Structure-specificity relationships of an intracellular xylanase from Geobacillus stearothermophilus.
  Acta Crystallogr D Biol Crystallogr, 63, 845-859.
PDB code: 2q8x
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