2fcq: Difference between revisions

Revision as of 18:20, 21 February 2008

X-ray Crystal Structure of a Chemically Synthesized Ubiquitin with a Cubic Space Group

OverviewOverview

The alpha-helix is a fundamental protein structural motif and is frequently terminated by a glycine residue. Explanations for the predominance of glycine at the C-cap terminal portions of alpha-helices have invoked uniquely favorable energetics of this residue in a left-handed conformation or enhanced solvation of the peptide backbone because of the absence of a side chain. Attempts to quantify the contributions of these two effects have been made previously, but the issue remains unresolved. Here we have used chemical protein synthesis to dissect the energetic basis of alpha-helix termination by comparing a series of ubiquitin variants containing an L-amino acid or the corresponding D-amino acid at the C-cap Gly35 position. D-Amino acids can adopt a left-handed conformation without energetic penalty, so the contributions of conformational strain and backbone solvation can thus be separated. Analysis of the thermodynamic data revealed that the preference for glycine at the C' position of a helix is predominantly a conformational effect.

About this StructureAbout this Structure

2FCQ is a Single protein structure of sequence from [1] with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Dissecting the energetics of protein alpha-helix C-cap termination through chemical protein synthesis., Bang D, Gribenko AV, Tereshko V, Kossiakoff AA, Kent SB, Makhatadze GI, Nat Chem Biol. 2006 Mar;2(3):139-43. Epub 2006 Jan 30. PMID:16446709

Page seeded by OCA on Thu Feb 21 17:20:01 2008

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OCA

@@ Line 1: / Line 1: @@
-[[Image:2fcq.gif|left|200px]]<br />
+[[Image:2fcq.gif|left|200px]]<br /><applet load="2fcq" size="350" color="white" frame="true" align="right" spinBox="true"
-<applet load="2fcq" size="450" color="white" frame="true" align="right" spinBox="true"
 caption="2fcq, resolution 3.30&Aring;" />
 '''X-ray Crystal Structure of a Chemically Synthesized Ubiquitin with a Cubic Space Group'''<br />
 ==Overview==
-The alpha-helix is a fundamental protein structural motif and is, frequently terminated by a glycine residue. Explanations for the, predominance of glycine at the C-cap terminal portions of alpha-helices, have invoked uniquely favorable energetics of this residue in a, left-handed conformation or enhanced solvation of the peptide backbone, because of the absence of a side chain. Attempts to quantify the, contributions of these two effects have been made previously, but the, issue remains unresolved. Here we have used chemical protein synthesis to, dissect the energetic basis of alpha-helix termination by comparing a, series of ubiquitin variants containing an L-amino acid or the, corresponding D-amino acid at the C-cap Gly35 position. D-Amino acids can, adopt a left-handed conformation without energetic penalty, so the, contributions of conformational strain and backbone solvation can thus be, separated. Analysis of the thermodynamic data revealed that the preference, for glycine at the C' position of a helix is predominantly a, conformational effect.
+The alpha-helix is a fundamental protein structural motif and is frequently terminated by a glycine residue. Explanations for the predominance of glycine at the C-cap terminal portions of alpha-helices have invoked uniquely favorable energetics of this residue in a left-handed conformation or enhanced solvation of the peptide backbone because of the absence of a side chain. Attempts to quantify the contributions of these two effects have been made previously, but the issue remains unresolved. Here we have used chemical protein synthesis to dissect the energetic basis of alpha-helix termination by comparing a series of ubiquitin variants containing an L-amino acid or the corresponding D-amino acid at the C-cap Gly35 position. D-Amino acids can adopt a left-handed conformation without energetic penalty, so the contributions of conformational strain and backbone solvation can thus be separated. Analysis of the thermodynamic data revealed that the preference for glycine at the C' position of a helix is predominantly a conformational effect.
 ==About this Structure==
-FCQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with CD as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2FCQ OCA].
+FCQ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=CD:'>CD</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FCQ OCA].
 ==Reference==
@@ Line 14: / Line 13: @@
 [[Category: Single protein]]
 [[Category: Bang, D.]]
-[[Category: Gribenko, A.V.]]
+[[Category: Gribenko, A V.]]
-[[Category: Kent, S.B.]]
+[[Category: Kent, S B.]]
-[[Category: Kossiakoff, A.A.]]
+[[Category: Kossiakoff, A A.]]
-[[Category: Makhatadze, G.I.]]
+[[Category: Makhatadze, G I.]]
 [[Category: Tereshko, V.]]
 [[Category: CD]]
 [[Category: ubiquitin]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 12 22:03:25 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:20:01 2008''