2b7x

Sequential reorganization of beta-sheet topology by insertion of a single strand

spinqualitylabelsall models 2b7x, resolution 3.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2b7x is a 4 chain structure with sequence from Escherichia virus T4. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 3Å Ligands: SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ENLYS_BPT4 Endolysin with lysozyme activity that degrades host peptidoglycans and participates with the holin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles. Once the holin has permeabilized the host cell membrane, the endolysin can reach the periplasm and break down the peptidoglycan layer. 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 PubMed Insertions, duplications, and deletions of sequence segments are thought to be major evolutionary mechanisms that increase the structural and functional diversity of proteins. Alternative splicing, for example, is an intracellular editing mechanism that is thought to generate isoforms for 30%-50% of all human genes. Whereas the inserted sequences usually display only minor structural rearrangements at the insertion site, recent observations indicate that they may also cause more dramatic structural displacements of adjacent structures. In the present study we test how artificially inserted sequences change the structure of the beta-sheet region in T4 lysozyme. Copies of two different beta-strands were inserted into two different loops of the beta-sheet, and the structures were determined. Not surprisingly, one insert "loops out" at its insertion site and forms a new small beta-hairpin structure. Unexpectedly, however, the second insertion leads to displacement of adjacent strands and a sequential reorganization of the beta-sheet topology. Even though the insertions were performed at two different sites, looping out occurred at the C-terminal end of the same beta-strand. Reasons as to why a non-native sequence would be recruited to replace that which occurs in the native protein are discussed. Our results illustrate how sequence insertions can facilitate protein evolution through both local and nonlocal changes in structure. Sequential reorganization of beta-sheet topology by insertion of a single strand.,Sagermann M, Baase WA, Matthews BW Protein Sci. 2006 May;15(5):1085-92. Epub 2006 Apr 5. PMID:16597830 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Lysozyme 3D structures

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