152l
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CONSERVATION OF SOLVENT-BINDING SITES IN 10 CRYSTAL FORMS OF T4 LYSOZYME
OverviewOverview
Solvent-binding sites were compared in 10 different crystal forms of phage, T4 lysozyme that were refined using data from 2.6 A to 1.7 A resolution., The sample included 18 crystallographically independent lysozyme, molecules. Despite different crystallization conditions, variable crystal, contacts, changes due to mutation, and varying attention to solvent during, crystallographic refinement, 62% of the 20 most frequently occupied sites, were conserved. Allowing for potential steric interference from, neighboring molecules in the crystal lattice, this fraction increased to, 79% of the sites. There was, however, no solvent-binding site that was, occupied in all 18 lysozyme molecules. A buried double site was occupied, in 17 instances and 2 other internal sites were occupied 15 times. Apart, from these buried sites, the most frequently occupied sites were often at, the amino-termini of alpha-helices. Solvent molecules at the most, conserved sites tended to have crystallographic thermal factors lower than, average, but atoms with low B-factors were not restricted to these sites., Although superficial inspection may suggest that only 50-60% (or less) of, solvent-binding sites are conserved in different crystal forms of a, protein, it appears that many sites appear to be empty either because of, steric interference or because the apparent occupancy of a given site can, vary from crystal to crystal. The X-ray method of identifying sites is, somewhat subjective and tends to result in specification only of those, solvent molecules that are well ordered and bound with high occupancy, even though there is clear evidence for solvent bound at many additional, sites.(ABSTRACT TRUNCATED AT 250 WORDS)
About this StructureAbout this Structure
152L is a Single protein structure of sequence from Enterobacteria phage t2 with SO4 as ligand. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
ReferenceReference
Conservation of solvent-binding sites in 10 crystal forms of T4 lysozyme., Zhang XJ, Matthews BW, Protein Sci. 1994 Jul;3(7):1031-9. PMID:7920248
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