1L32: REPLACEMENTS OF PRO86 IN PHAGE T4 LYSOZYME EXTEND AN ALPHA-HELIX BUT DO NOT ALTER PROTEIN STABILITY

Citation:
Abstract
To investigate the relation between protein stability and the predicted stabilities of individual secondary structural elements, residue Pro86 in an alpha-helix in phage T4 lysozyme was replaced by ten different amino acids. The x-ray crystal structures of seven of the mutant lysozymes were determined at high resolution. In each case, replacement of the proline resulted in the formation of an extended alpha-helix. This involves a large conformational change in residues 81 to 83 and smaller shifts that extend 20 angstroms across the protein surface. Unexpectedly, all ten amino acid substitutions marginally reduce protein thermostability. This insensitivity of stability to the amino acid at position 86 is not simply explained by statistical and thermodynamic criteria for helical propensity. The observed conformational changes illustrate a general mechanism by which proteins can tolerate mutations.
PDB ID: 1L32Download
MMDB ID: 56625
PDB Deposition Date: 1989/5/1
Updated in MMDB: 2017/12
Experimental Method:
x-ray diffraction
Resolution: 1.7  Å
Source Organism:
Similar Structures:
Biological Unit for 1L32: monomeric; determined by author
Molecular Components in 1L32
Label Count Molecule
Protein (1 molecule)
1
T4 Lysozyme(Gene symbol: e)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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