1ey8

STRUCTURE OF S. NUCLEASE STABILIZING TRIPLE MUTANT P117G/H124L/S128A

spinqualitylabelsall models 1ey8, resolution 1.75Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1ey8 is a 1 chain structure with sequence from "micrococcus_aureus"_(rosenbach_1884)_zopf_1885 "micrococcus aureus" (rosenbach 1884) zopf 1885. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1ey0, 1ey4, 1ey5, 1ey6, 1ey7, 1ey9, 1eya, 1eyc, 1eyd, 1ez6, 1ez8 Activity: Micrococcal nuclease, with EC number 3.1.31.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [NUC_STAAU] Enzyme that catalyzes the hydrolysis of both DNA and RNA at the 5' position of the phosphodiester bond. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Seven hyper-stable multiple mutants have been constructed in staphylococcal nuclease by various combinations of eight different stabilizing single mutants. The stabilities of these multiple mutants determined by guanidine hydrochloride denaturation were 3.4 to 5.6 kcal/mol higher than that of the wild-type. Their thermal denaturation midpoint temperatures were 12.6 to 22.9 deg. C higher than that of the wild-type. These are among the greatest increases in protein stability and thermal denaturation midpoint temperature relative to the wild-type yet attained. There has been great interest in understanding how proteins found in thermophilic organisms are stabilized. One frequently cited theory is that the packing of hydrophobic side-chains is improved in the cores of proteins isolated from thermophiles when compared to proteins from mesophiles. The crystal structures of four single and five multiple stabilizing mutants of staphylococcal nuclease were solved to high resolution. No large overall structural change was found, with most changes localized around the sites of mutation. Rearrangements were observed in the packing of side-chains in the major hydrophobic core, although none of the mutations was in the core. It is surprising that detailed structural analysis showed that packing had improved, with the volume of the mutant protein's hydrophobic cores decreasing as protein stability increased. Further, the number of van der Waals interactions in the entire protein showed an experimentally significant increase correlated with increasing stability. These results indicate that optimization of packing follows as a natural consequence of increased protein thermostability and that good packing is not necessarily the proximate cause of high stability. Another popular theory is that thermostable proteins have more electrostatic and hydrogen bonding interactions and these are responsible for the high stabilities. The mutants here show that increased numbers of electrostatic and hydrogen bonding interactions are not obligatory for large increases in protein stability. Increasing the thermostability of staphylococcal nuclease: implications for the origin of protein thermostability.,Chen J, Lu Z, Sakon J, Stites WE J Mol Biol. 2000 Oct 20;303(2):125-30. PMID:11023780 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Staphylococcal nuclease

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