1wcr
From Proteopedia
(New page: 200px<br /><applet load="1wcr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1wcr" /> '''TRIMERIC STRUCTURE OF THE ENZYME IIA FROM ES...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1wcr.gif|left|200px]]<br /><applet load="1wcr" size=" | + | [[Image:1wcr.gif|left|200px]]<br /><applet load="1wcr" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1wcr" /> | caption="1wcr" /> | ||
'''TRIMERIC STRUCTURE OF THE ENZYME IIA FROM ESCHERICHIA COLI PHOSPHOTRANSFERASE SYSTEM SPECIFIC FOR N,N'-DIACETYLCHITOBIOSE'''<br /> | '''TRIMERIC STRUCTURE OF THE ENZYME IIA FROM ESCHERICHIA COLI PHOSPHOTRANSFERASE SYSTEM SPECIFIC FOR N,N'-DIACETYLCHITOBIOSE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The solution structure of trimeric Escherichia coli enzyme IIA(Chb) (34 | + | 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 Structure== | ==About this Structure== | ||
| - | 1WCR 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:// | + | 1WCR 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== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Protein-N(pi)-phosphohistidine--sugar phosphotransferase]] | [[Category: Protein-N(pi)-phosphohistidine--sugar phosphotransferase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Clore, G | + | [[Category: Clore, G M.]] |
[[Category: Tang, C.]] | [[Category: Tang, C.]] | ||
[[Category: chitobiose]] | [[Category: chitobiose]] | ||
| Line 24: | Line 24: | ||
[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:42:54 2008'' |
Revision as of 13:42, 21 February 2008
|
TRIMERIC STRUCTURE OF THE ENZYME IIA FROM ESCHERICHIA COLI PHOSPHOTRANSFERASE SYSTEM SPECIFIC FOR N,N'-DIACETYLCHITOBIOSE
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| > 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
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.
Reference
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
Page seeded by OCA on Thu Feb 21 15:42:54 2008
