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1l32
From Proteopedia
REPLACEMENTS OF PRO86 IN PHAGE T4 LYSOZYME EXTEND AN ALPHA-HELIX BUT DO NOT ALTER PROTEIN STABILITY
Overview
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.
About this Structure
1L32 is a Single protein structure of sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA.
Reference
Replacements of Pro86 in phage T4 lysozyme extend an alpha-helix but do not alter protein stability., Alber T, Bell JA, Sun DP, Nicholson H, Wozniak JA, Cook S, Matthews BW, Science. 1988 Feb 5;239(4840):631-5. PMID:3277275 Page seeded by OCA on Fri May 2 23:29:05 2008
