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The extraordinary thermal stability of EstA from S. islandicus is independent of post translational modifications
Author(s) -
StieflerJensen Daniel,
SchwarzLinnet Troels,
de Lichtenberg Casper,
Nguyen Tam T. T. N.,
Rand Kasper D.,
Huang Li,
She Qunxin,
Teilum Kaare
Publication year - 2017
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.3220
Subject(s) - lysine , thermophile , methylation , biology , biochemistry , archaea , protein methylation , enzyme , recombinant dna , sulfolobus solfataricus , mesophile , escherichia coli , methyltransferase , genetics , amino acid , bacteria , dna , gene
Enzymes from thermophilic and hyper‐thermophilic organisms have an intrinsic high stability. Understanding the mechanisms behind their high stability will be important knowledge for the engineering of novel enzymes with high stability. Lysine methylation of proteins is prevalent in Sulfolobus, a genus of hyperthermophilic and acidophilic archaea. Both unspecific and temperature dependent lysine methylations are seen, but the significance of this post‐translational modification has not been investigated. Here, we test the effect of eliminating in vivo lysine methylation on the stability of an esterase (EstA). The enzyme was purified from the native host S. islandicus as well as expressed as a recombinant protein in E. coli, a mesophilic host that does not code for any machinery for in vivo lysine methylation. We find that lysine mono methylation indeed has a positive effect on the stability of EstA, but the effect is small. The effect of the lysine methylation on protein stability is secondary to that of protein expression in E. coli , as the E. coli recombinant enzyme is compromised both on stability and activity. We conclude that these differences are not attributed to any covalent difference between the protein expressed in hyperthermophilic versus mesophilic hosts.