2lhm
CRYSTAL STRUCTURES OF THE APO-AND HOLOMUTANT HUMAN LYSOZYMES WITH AN INTRODUCED CA2+ BINDING SITE
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| , resolution 1.8Å | |||||||
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| Activity: | Lysozyme, with EC number 3.2.1.17 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
The three-dimensional structures of apo- and holomutant human lysozymes (D86/92 lysozyme), in which a calcium binding site was designed and created for enhancing molecular stability by replacing both Gln86 and Ala92 with aspartic acids, were refined at 1.8-A resolution by x-ray crystallography. The overall structures and crystallographic thermal factors of all three proteins, the apo-, holo-D86/92, and the wild-type human lysozymes, were essentially identical; these results showed that the introduction of the calcium binding site did not affect either the overall structure or molecular rigidity of the proteins. However, structure analyses of the apo-D86/92 lysozyme revealed that the mutations affected the side chain conformation of residue 86 and hydrogen networks between the protein and the internal solvent molecules. In the structure of the holo-D86/92 lysozyme, seven oxygen ligands formed a slightly distorted pentagonal bipyramid around the calcium ion, indicating that the coordination around the calcium ion was quite similar to that in baboon alpha-lactalbumin. The pentagonal bipyramid coordination could be one of the most widely found and appropriate calcium binding schemes in proteins.
About this StructureAbout this Structure
2LHM is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of the apo- and holomutant human lysozymes with an introduced Ca2+ binding site., Inaka K, Kuroki R, Kikuchi M, Matsushima M, J Biol Chem. 1991 Nov 5;266(31):20666-71. PMID:1939116
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