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PDBsum entry 2kac

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protein links
Immune system PDB id
2kac
Jmol
Contents
Protein chain
64 a.a. *
* Residue conservation analysis
PDB id:
2kac
Name: Immune system
Title: Nmr solution structure of kx6e protl mutant
Structure: Protein l. Chain: a. Fragment: residues in database 111-173. Engineered: yes. Mutation: yes
Source: Peptostreptococcus magnus. Organism_taxid: 1260. Expressed in: escherichia coli. Expression_system_taxid: 562.
NMR struc: 20 models
Authors: B.Lopez-Mendez,X.Tadeo,M.Pons,O.Millet
Key ref: X.Tadeo et al. (2009). Structural basis for the aminoacid composition of proteins from halophilic archea. PLoS Biol, 7, e1000257. PubMed id: 20016684
Date:
04-Nov-08     Release date:   20-Oct-09    
PROCHECK
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 Headers
 References

Protein chain
Pfam   ArchSchema ?
Q51912  (Q51912_PEPMA) -  Putative uncharacterized protein
Seq:
Struc:
 
Seq:
Struc:
719 a.a.
64 a.a.*
Key:    PfamA domain  PfamB domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 8 residue positions (black crosses)

 

 
PLoS Biol 7:e1000257 (2009)
PubMed id: 20016684  
 
 
Structural basis for the aminoacid composition of proteins from halophilic archea.
X.Tadeo, B.López-Méndez, T.Trigueros, A.Laín, D.Castaño, O.Millet.
 
  ABSTRACT  
 
Proteins from halophilic organisms, which live in extreme saline conditions, have evolved to remain folded at very high ionic strengths. The surfaces of halophilic proteins show a biased amino acid composition with a high prevalence of aspartic and glutamic acids, a low frequency of lysine, and a high occurrence of amino acids with a low hydrophobic character. Using extensive mutational studies on the protein surfaces, we show that it is possible to decrease the salt dependence of a typical halophilic protein to the level of a mesophilic form and engineer a protein from a mesophilic organism into an obligate halophilic form. NMR studies demonstrate complete preservation of the three-dimensional structure of extreme mutants and confirm that salt dependency is conferred exclusively by surface residues. In spite of the statistically established fact that most halophilic proteins are strongly acidic, analysis of a very large number of mutants showed that the effect of salt on protein stability is largely independent of the total protein charge. Conversely, we quantitatively demonstrate that halophilicity is directly related to a decrease in the accessible surface area.
 

Literature references that cite this PDB file's key reference

  PubMed id Reference
21539921 F.Liu, J.Xiong, S.Kumar, C.Yang, S.Ge, S.Li, N.Xia, and K.Swaminathan (2011).
Structural and biophysical characterization of Mycobacterium tuberculosis dodecin Rv1498A.
  J Struct Biol, 175, 31-38.
PDB code: 3oqt
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.