1wcr: Difference between revisions

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TRIMERIC STRUCTURE OF THE ENZYME IIA FROM ESCHERICHIA COLI PHOSPHOTRANSFERASE SYSTEM SPECIFIC FOR N,N'-DIACETYLCHITOBIOSE

OverviewOverview

The solution structure of trimeric Escherichia coli enzyme IIA(Chb) (34 kDa), a component of the N,N'-diacetylchitobiose/lactose branch of the phosphotransferase signal transduction system, has been determined by NMR spectroscopy. Backbone residual dipolar couplings were used to provide long range orientational restraints, and long range (|i - j| > or = 5 residues) nuclear Overhauser enhancement restraints were derived exclusively from samples in which at least one subunit was 15N/13C/2H/(Val-Leu-Ile)-methyl-protonated. Each subunit consists of a three-helix bundle. Hydrophobic residues lining helix 3 of each subunit are largely responsible for the formation of a parallel coiled-coil trimer. The active site histidines (His-89 from each subunit) are located in three symmetrically placed deep crevices located at the interface of two adjacent subunits (A and C, C and B, and B and A). Partially shielded from bulk solvent, structural modeling suggests that phosphorylated His-89 is stabilized by electrostatic interactions with the side chains of His-93 from the same subunit and Gln-91 from the adjacent subunit. Comparison with the x-ray structure of Lactobacillus lactis IIA(Lac) reveals some substantial structural differences, particularly in regard to helix 3, which exhibits a 40 degrees kink in IIA(Lac) versus a 7 degrees bend in IIA(Chb). This is associated with the presence of an unusually large (230-angstroms3) buried hydrophobic cavity at the trimer interface in IIA(Lac) that is reduced to only 45 angstroms3) in IIA(Chb).

About this StructureAbout this Structure

1WCR is a Single protein structure of sequence from Escherichia coli. Active as Protein-N(pi)-phosphohistidine--sugar phosphotransferase, with EC number 2.7.1.69 Full crystallographic information is available from OCA.

ReferenceReference

Solution structure of enzyme IIA(Chitobiose) from the N,N'-diacetylchitobiose branch of the Escherichia coli phosphotransferase system., Tang C, Williams DC Jr, Ghirlando R, Clore GM, J Biol Chem. 2005 Mar 25;280(12):11770-80. Epub 2005 Jan 14. PMID:15654077

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-[[Image:1wcr.gif|left|200px]]<br /><applet load="1wcr" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1wcr.gif|left|200px]]<br /><applet load="1wcr" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1wcr" />
 '''TRIMERIC STRUCTURE OF THE ENZYME IIA FROM ESCHERICHIA COLI PHOSPHOTRANSFERASE SYSTEM SPECIFIC FOR N,N'-DIACETYLCHITOBIOSE'''<br />
 ==Overview==
-The solution structure of trimeric Escherichia coli enzyme IIA(Chb) (34, kDa), a component of the N,N'-diacetylchitobiose/lactose branch of the, phosphotransferase signal transduction system, has been determined by NMR, spectroscopy. Backbone residual dipolar couplings were used to provide, long range orientational restraints, and long range (|i - j| &gt; or = 5, residues) nuclear Overhauser enhancement restraints were derived, exclusively from samples in which at least one subunit was, 15N/13C/2H/(Val-Leu-Ile)-methyl-protonated. Each subunit consists of a, three-helix bundle. Hydrophobic residues lining helix 3 of each subunit, are largely responsible for the formation of a parallel coiled-coil, trimer. The active site histidines (His-89 from each subunit) are located, in three symmetrically placed deep crevices located at the interface of, two adjacent subunits (A and C, C and B, and B and A). Partially shielded, from bulk solvent, structural modeling suggests that phosphorylated His-89, is stabilized by electrostatic interactions with the side chains of His-93, from the same subunit and Gln-91 from the adjacent subunit. Comparison, with the x-ray structure of Lactobacillus lactis IIA(Lac) reveals some, substantial structural differences, particularly in regard to helix 3, which exhibits a 40 degrees kink in IIA(Lac) versus a 7 degrees bend in, IIA(Chb). This is associated with the presence of an unusually large, (230-angstroms3) buried hydrophobic cavity at the trimer interface in, IIA(Lac) that is reduced to only 45 angstroms3) in IIA(Chb).
+The solution structure of trimeric Escherichia coli enzyme IIA(Chb) (34 kDa), a component of the N,N'-diacetylchitobiose/lactose branch of the phosphotransferase signal transduction system, has been determined by NMR spectroscopy. Backbone residual dipolar couplings were used to provide long range orientational restraints, and long range (|i - j| &gt; or = 5 residues) nuclear Overhauser enhancement restraints were derived exclusively from samples in which at least one subunit was 15N/13C/2H/(Val-Leu-Ile)-methyl-protonated. Each subunit consists of a three-helix bundle. Hydrophobic residues lining helix 3 of each subunit are largely responsible for the formation of a parallel coiled-coil trimer. The active site histidines (His-89 from each subunit) are located in three symmetrically placed deep crevices located at the interface of two adjacent subunits (A and C, C and B, and B and A). Partially shielded from bulk solvent, structural modeling suggests that phosphorylated His-89 is stabilized by electrostatic interactions with the side chains of His-93 from the same subunit and Gln-91 from the adjacent subunit. Comparison with the x-ray structure of Lactobacillus lactis IIA(Lac) reveals some substantial structural differences, particularly in regard to helix 3, which exhibits a 40 degrees kink in IIA(Lac) versus a 7 degrees bend in IIA(Chb). This is associated with the presence of an unusually large (230-angstroms3) buried hydrophobic cavity at the trimer interface in IIA(Lac) that is reduced to only 45 angstroms3) in IIA(Chb).
 ==About this Structure==
-WCR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Protein-N(pi)-phosphohistidine--sugar_phosphotransferase Protein-N(pi)-phosphohistidine--sugar phosphotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.69 2.7.1.69] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1WCR OCA].
+WCR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Active as [http://en.wikipedia.org/wiki/Protein-N(pi)-phosphohistidine--sugar_phosphotransferase Protein-N(pi)-phosphohistidine--sugar phosphotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.69 2.7.1.69] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WCR OCA].
 ==Reference==
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 [[Category: Protein-N(pi)-phosphohistidine--sugar phosphotransferase]]
 [[Category: Single protein]]
-[[Category: Clore, G.M.]]
+[[Category: Clore, G M.]]
 [[Category: Tang, C.]]
 [[Category: chitobiose]]
@@ Line 24: / Line 24: @@
 [[Category: transferase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 05:18:44 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:42:54 2008''