2KAC

NMR solution structure of KX6E protL mutant

Summary for 2KAC

• Entry DOI: 10.2210/pdb2kac/pdb
• Descriptor: Protein L (1 entity in total)
• Functional Keywords: protein, cell wall, peptidoglycan-anchor, immune system
• Biological source: Peptostreptococcus magnus
• Total number of polymer chains: 1
• Total formula weight: 7021.36

Authors

Lopez-Mendez, B.,Tadeo, X.,Pons, M.,Millet, O. (deposition date: 2008-11-04, release date: 2009-10-20, Last modification date: 2024-05-29)

Primary citation

Tadeo, X.,Lopez-Mendez, B.,Trigueros, T.,Lain, A.,Castano, D.,Millet, O.
Structural basis for the aminoacid composition of proteins from halophilic archea
Plos Biol., 7:e1000257-e1000257, 2009

PubMed 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.

PubMed: 20016684
DOI: 10.1371/journal.pbio.1000257

Experimental method

SOLUTION NMR