1t97

==Use of sequence duplication to engineer a ligand-triggered long-distance molecular switch in T4 lysosyme==

<StructureSection load='1t97' size='340' side='right' caption='[[1t97]], [[Resolution|resolution]] 2.70&Aring;' scene=''>

<table><tr><td colspan='2'>[[1t97]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t4 Enterobacteria phage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T97 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1T97 FirstGlance]. <br>

</td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">E ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10665 Enterobacteria phage T4])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1t97 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1t97 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1t97 RCSB], [http://www.ebi.ac.uk/pdbsum/1t97 PDBsum]</span></td></tr>

[[http://www.uniprot.org/uniprot/LYS_BPT4 LYS_BPT4]] Helps to release the mature phage particles from the cell wall by breaking down the peptidoglycan.

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/t9/1t97_consurf.spt"</scriptWhenChecked>

</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].

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== Publication Abstract from PubMed ==

We have designed a molecular switch in a T4 lysozyme construct that controls a large-scale translation of a duplicated helix. As shown by crystal structures of the construct with the switch on and off, the conformational change is triggered by the binding of a ligand (guanidinium ion) to a site that in the wild-type protein was occupied by the guanidino head group of an Arg. In the design template, a duplicated helix is flanked by two loop regions of different stabilities. In the "on" state, the N-terminal loop is weakly structured, whereas the C-terminal loop has a well defined conformation that is stabilized by means of nonbonded interactions with the Arg head group. The truncation of the Arg to Ala destabilizes this loop and switches the protein to the "off" state, in which the duplicated helix is translocated approximately 20 A. Guanidinium binding restores the key interactions, restabilizes the C-terminal loop, and restores the "on" state. Thus, the presence of an external ligand, which is unrelated to the catalytic activity of the enzyme, triggers the inserted helix to translate 20 A away from the binding site. The results illustrate a proposed mechanism for protein evolution in which sequence duplication followed by point mutation can lead to the establishment of new function.

Use of sequence duplication to engineer a ligand-triggered, long-distance molecular switch in T4 lysozyme.,Yousef MS, Baase WA, Matthews BW Proc Natl Acad Sci U S A. 2004 Aug 10;101(32):11583-6. Epub 2004 Jul 30. PMID:15286283<ref>PMID:15286283</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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[[Category: Enterobacteria phage t4]]

[[Category: Lysozyme]]

[[Category: Baase, W A]]

[[Category: Matthews, B W]]

[[Category: Yousef, M S]]

[[Category: T4 lysozyme]]