1l35
STRUCTURE OF A THERMOSTABLE DISULFIDE-BRIDGE MUTANT OF PHAGE T4 LYSOZYME SHOWS THAT AN ENGINEERED CROSSLINK IN A FLEXIBLE REGION DOES NOT INCREASE THE RIGIDITY OF THE FOLDED PROTEIN
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OverviewOverview
A disulfide bond introduced between amino acid positions 9 and 164 in, phage T4 lysozyme has been shown to significantly increase the stability, of the enzyme toward thermal denaturation [Matsumura, M., Becktel, W.J., Levitt, M., & Matthews, B. W. (1989) Proc. Natl. Acad. Sci. U.S.A. 86, 6562-6566]. To elucidate the structural features of the engineered, disulfide, the crystal structure of the disulfide mutant has been, determined at 1.8-A resolution. Residue 9 lies in the N-terminal, alpha-helix, while residue 164 is located at the extreme C terminus of T4, lysozyme, which is the most mobile part of the molecule. The refined, structure shows that the formation of the disulfide bond is accompanied by, relatively large (approximately 2.5 A) localized shifts in C-terminal, main-chain atoms. Comparison of the geometry of the engineered disulfide, with those of naturally observed disulfides in proteins shows that the, engineered bridge adopts a left-handed spiral conformation with a typical, set of dihedral angles and C alpha-C alpha distance. The geometry of the, engineered disulfide suggests that it is slightly more strained than the, disulfide of oxidized dithiothreitol but that the strain is within the, range observed in naturally occurring disulfides. The wild-type and, cross-linked lysozymes have very similar overall crystallographic, temperature factors, indicating that the introduction of the disulfide, bond does not impose rigidity on the folded protein structure. In, particular, residues 162-164 retain high mobility in the mutant structure, consistent with the idea that stabilization of the protein is due to the, effect of the disulfide cross-link on the unfolded rather than the folded, state.(ABSTRACT TRUNCATED AT 250 WORDS)
About this StructureAbout this Structure
1L35 is a Single protein structure of sequence from Bacteriophage t4. The following page contains interesting information on the relation of 1L35 with [Lysozyme]. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
ReferenceReference
Structure of a thermostable disulfide-bridge mutant of phage T4 lysozyme shows that an engineered cross-link in a flexible region does not increase the rigidity of the folded protein., Pjura PE, Matsumura M, Wozniak JA, Matthews BW, Biochemistry. 1990 Mar 13;29(10):2592-8. PMID:2334683
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