1l23 | pdb_00001l23

ENHANCED PROTEIN THERMOSTABILITY FROM SITE-DIRECTED MUTATIONS THAT DECREASE THE ENTROPY OF UNFOLDING

spinqualitylabelsall models 1l23, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1l23 is a 1 chain structure with sequence from Escherichia virus T4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.7Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ENLYS_BPT4 Endolysin with lysozyme activity that degrades host peptidoglycans and participates with the holin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles. Once the holin has permeabilized the host cell membrane, the endolysin can reach the periplasm and break down the peptidoglycan layer. 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 It is proposed that the stability of a protein can be increased by selected amino acid substitutions that decrease the configurational entropy of unfolding. Two such substitutions, one of the form Xaa----Pro and the other of the form Gly----Xaa, were constructed in bacteriophage T4 lysozyme at sites consistent with the known three-dimensional structure. Both substitutions stabilize the protein toward reversible and irreversible thermal denaturation at physiological pH. The substitutions have no effect on enzymatic activity. High-resolution crystallographic analysis of the proline-containing mutant protein (Ala-82----Pro) shows that its three-dimensional structure is essentially identical with the wild-type enzyme. The overall structure of the other mutant enzyme (Gly-77----Ala) is also very similar to wild-type lysozyme, although there are localized conformational adjustments in the vicinity of the altered amino acid. The combination of a number of such amino acid replacements, each of which is expected to contribute approximately 1 kcal/mol (1 cal = 4.184 J) to the free energy of folding, may provide a general strategy for substantial improvement in the stability of a protein. Enhanced protein thermostability from site-directed mutations that decrease the entropy of unfolding.,Matthews BW, Nicholson H, Becktel WJ Proc Natl Acad Sci U S A. 1987 Oct;84(19):6663-7. PMID:3477797 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Lysozyme 3D structures

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