2igc: Difference between revisions

Revision as of 18:52, 21 February 2008

Structure of Spin labeled T4 Lysozyme Mutant T115R1A

OverviewOverview

A nitroxide side chain (R1) has been substituted at single sites along a helix-turn-helix motif in T4 lysozyme (residues 114-135). Together with previously published data, the new sites reported complete a continuous scan through the motif. Mutants with R1 at sites 115 and 118 were selected for crystallographic analysis to identify the structural origins of the corresponding two-component EPR spectra. At 115, R1 is shown to occupy two rotamers in the room temperature crystal structure, one of which has not been previously reported. The two components in the EPR spectrum apparently arise from differential interactions of the two rotamers with the surrounding structure, the most important of which is a hydrophobic interaction of the nitroxide ring. Interestingly, the crystal structure at 100 K reveals a single rotamer, emphasizing the possibility of rotamer selection in low-temperature crystal structures. Residue 118 is at a solvent-inaccessible site in the protein core, and the structure of 118R1, the first reported for the R1 side chain at a buried site, reveals how the side chain is accommodated in an overpacked core.

About this StructureAbout this Structure

2IGC is a Single protein structure of sequence from Bacteriophage t4. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.

ReferenceReference

Structural determinants of nitroxide motion in spin-labeled proteins: tertiary contact and solvent-inaccessible sites in helix G of T4 lysozyme., Guo Z, Cascio D, Hideg K, Kalai T, Hubbell WL, Protein Sci. 2007 Jun;16(6):1069-86. Epub 2007 May 1. PMID:17473014

Page seeded by OCA on Thu Feb 21 17:52:29 2008

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OCA

@@ Line 4: / Line 4: @@
 ==Overview==
-A nitroxide side chain (R1) has been substituted at single sites along a, helix-turn-helix motif in T4 lysozyme (residues 114-135). Together with, previously published data, the new sites reported complete a continuous, scan through the motif. Mutants with R1 at sites 115 and 118 were selected, for crystallographic analysis to identify the structural origins of the, corresponding two-component EPR spectra. At 115, R1 is shown to occupy two, rotamers in the room temperature crystal structure, one of which has not, been previously reported. The two components in the EPR spectrum, apparently arise from differential interactions of the two rotamers with, the surrounding structure, the most important of which is a hydrophobic, interaction of the nitroxide ring. Interestingly, the crystal structure at, 100 K reveals a single rotamer, emphasizing the possibility of rotamer, selection in low-temperature crystal structures. Residue 118 is at a, solvent-inaccessible site in the protein core, and the structure of 118R1, the first reported for the R1 side chain at a buried site, reveals how the, side chain is accommodated in an overpacked core.
+A nitroxide side chain (R1) has been substituted at single sites along a helix-turn-helix motif in T4 lysozyme (residues 114-135). Together with previously published data, the new sites reported complete a continuous scan through the motif. Mutants with R1 at sites 115 and 118 were selected for crystallographic analysis to identify the structural origins of the corresponding two-component EPR spectra. At 115, R1 is shown to occupy two rotamers in the room temperature crystal structure, one of which has not been previously reported. The two components in the EPR spectrum apparently arise from differential interactions of the two rotamers with the surrounding structure, the most important of which is a hydrophobic interaction of the nitroxide ring. Interestingly, the crystal structure at 100 K reveals a single rotamer, emphasizing the possibility of rotamer selection in low-temperature crystal structures. Residue 118 is at a solvent-inaccessible site in the protein core, and the structure of 118R1, the first reported for the R1 side chain at a buried site, reveals how the side chain is accommodated in an overpacked core.
 ==About this Structure==
@@ Line 10: / Line 10: @@
 ==Reference==
-Structural determinants of nitroxide motion in spin-labeled proteins: Tertiary contact and solvent-inaccessible sites in helix G of T4 lysozyme., Guo Z, Cascio D, Hideg K, Kalai T, Hubbell WL, Protein Sci. 2007 Jun;16(6):1069-86. Epub 2007 May 1. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17473014 17473014]
+Structural determinants of nitroxide motion in spin-labeled proteins: tertiary contact and solvent-inaccessible sites in helix G of T4 lysozyme., Guo Z, Cascio D, Hideg K, Kalai T, Hubbell WL, Protein Sci. 2007 Jun;16(6):1069-86. Epub 2007 May 1. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17473014 17473014]
 [[Category: Bacteriophage t4]]
 [[Category: Lysozyme]]
@@ Line 17: / Line 17: @@
 [[Category: Guo, Z.]]
 [[Category: Hideg, K.]]
-[[Category: Hubbell, W.L.]]
+[[Category: Hubbell, W L.]]
 [[Category: epr]]
 [[Category: nitroxide]]
@@ Line 23: / Line 23: @@
 [[Category: t4 lysozyme]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 14:54:39 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:52:29 2008''