1l96 | pdb_00001l96
STRUCTURE OF A HINGE-BENDING BACTERIOPHAGE T4 LYSOZYME MUTANT, ILE3-> PRO
Structural highlights
Function[LYS_BPT4] Helps to release the mature phage particles from the cell wall by breaking down the peptidoglycan. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe mutant T4 phage lysozyme in which isoleucine 3 is replaced by proline (I3P) crystallizes in an orthorhombic form with two independent molecules in the asymmetric unit. Relative to wild-type lysozyme, which crystallizes in a trigonal form, the two I3P molecules undergo large hinge-bending displacements with the alignments of the amino-terminal and carboxy-terminal domains changed by 28.9 degrees and 32.9 degrees, respectively. The introduction of the mutation, together with the hinge-bending displacement, is associated with repacking of the side-chains of Phe4, Phe67 and Phe104. These aromatic residues are clustered close to the site of the mutation and are at the junction between the amino and carboxyl-terminal domains. As a result of this structural rearrangement the side-chain of Phe4 moves from a relatively solvent-exposed conformation to one that is largely buried. Mutant I3P also crystallizes in the same trigonal form as wild-type and, in this case, the observed structural changes are restricted to the immediate vicinity of the replacement. The main change is a shift of 0.3 to 0.5 A in the backbone of residues 1 to 5. The ability to crystallize I3P under similar conditions but in substantially different conformations suggests that the molecule undergoes large-scale hinge-bending displacements in solution. It is also likely that these conformational excursions are associated with repacking at the junction of the N-terminal and C-terminal domains. On the other hand, the analysis is complicated by possible effects of crystal packing. The different I3P crystal structures show substantial differences in the binding of solvent, both at the site of the Ile3-->Pro replacement and at other internal sites. Structure of a hinge-bending bacteriophage T4 lysozyme mutant, Ile3-->Pro.,Dixon MM, Nicholson H, Shewchuk L, Baase WA, Matthews BW J Mol Biol. 1992 Oct 5;227(3):917-33. PMID:1404394[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
