3at1
From Proteopedia
(New page: 200px<br /><applet load="3at1" size="450" color="white" frame="true" align="right" spinBox="true" caption="3at1, resolution 2.8Å" /> '''CRYSTAL STRUCTURES OF...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:3at1.jpg|left|200px]]<br /><applet load="3at1" size=" | + | [[Image:3at1.jpg|left|200px]]<br /><applet load="3at1" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="3at1, resolution 2.8Å" /> | caption="3at1, resolution 2.8Å" /> | ||
'''CRYSTAL STRUCTURES OF PHOSPHONOACETAMIDE LIGATED T AND PHOSPHONOACETAMIDE AND MALONATE LIGATED R STATES OF ASPARTATE CARBAMOYLTRANSFERASE AT 2.8-ANGSTROMS RESOLUTION AND NEUTRAL PH'''<br /> | '''CRYSTAL STRUCTURES OF PHOSPHONOACETAMIDE LIGATED T AND PHOSPHONOACETAMIDE AND MALONATE LIGATED R STATES OF ASPARTATE CARBAMOYLTRANSFERASE AT 2.8-ANGSTROMS RESOLUTION AND NEUTRAL PH'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The T----R transition of the cooperative enzyme aspartate | + | The T----R transition of the cooperative enzyme aspartate carbamoyltransferase occurs at pH 7 in single crystals without visibly cracking many of the crystals and leaving those uncracked suitable for single-crystal X-ray analysis. To promote the T----R transition, we employ the competitive inhibitors of carbamoyl phosphate and aspartate, which are phosphonoacetamide (PAM) and malonate, respectively. In response to PAM binding to the T-state crystals, residues Thr 53-Thr 55 and Pro 266-Pro 268 move to their R-state positions to bind to the phosphonate and amino group of PAM. These changes induce a conformation that can bind tightly the aspartate analogue malonate, which thereby effects the allosteric transition. We prove this by showing that PAM-ligated T-state crystals (Tpam), space group P321 (a = 122.2 A, c = 142.2 A), when transferred to a solution containing 20 mM PAM and 8 mM malonate at pH 7, isomerize to R-state crystals (Rpam,mal,soak), space group also P321 (a = 122.2 A, c = 156.4 A). The R-state structure in which the T----R transition occurs within the crystal at pH 7 compares very well (rms = 0.19 A for all atoms) with an R-state structure determined at pH 7 in which the crystals were initially grown in a solution of PAM and malonate at pH 5.9 and subsequently transferred to a buffer containing the ligands at pH 7 (Rpam,mal,crys). In fact, both of the PAM and malonate ligated R-state structures are very similar to both the carbamoyl phosphate and succinate or the N-(phosphonoacetyl)-L-aspartate ligated structures, even though the R-state structures reported here were determined at pH 7. Crystallographic residuals refined to 0.16-0.18 at 2.8-A resolution for the three structures. |
==About this Structure== | ==About this Structure== | ||
| - | 3AT1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ZN and PCT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate_carbamoyltransferase Aspartate carbamoyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.3.2 2.1.3.2] Full crystallographic information is available from [http:// | + | 3AT1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=PCT:'>PCT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate_carbamoyltransferase Aspartate carbamoyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.3.2 2.1.3.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3AT1 OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Gouaux, J | + | [[Category: Gouaux, J E.]] |
| - | [[Category: Lipscomb, W | + | [[Category: Lipscomb, W N.]] |
[[Category: PCT]] | [[Category: PCT]] | ||
[[Category: ZN]] | [[Category: ZN]] | ||
| Line 21: | Line 21: | ||
[[Category: transferase (carbamoyl-p]] | [[Category: transferase (carbamoyl-p]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:02:49 2008'' |
Revision as of 17:02, 21 February 2008
|
CRYSTAL STRUCTURES OF PHOSPHONOACETAMIDE LIGATED T AND PHOSPHONOACETAMIDE AND MALONATE LIGATED R STATES OF ASPARTATE CARBAMOYLTRANSFERASE AT 2.8-ANGSTROMS RESOLUTION AND NEUTRAL PH
Overview
The T----R transition of the cooperative enzyme aspartate carbamoyltransferase occurs at pH 7 in single crystals without visibly cracking many of the crystals and leaving those uncracked suitable for single-crystal X-ray analysis. To promote the T----R transition, we employ the competitive inhibitors of carbamoyl phosphate and aspartate, which are phosphonoacetamide (PAM) and malonate, respectively. In response to PAM binding to the T-state crystals, residues Thr 53-Thr 55 and Pro 266-Pro 268 move to their R-state positions to bind to the phosphonate and amino group of PAM. These changes induce a conformation that can bind tightly the aspartate analogue malonate, which thereby effects the allosteric transition. We prove this by showing that PAM-ligated T-state crystals (Tpam), space group P321 (a = 122.2 A, c = 142.2 A), when transferred to a solution containing 20 mM PAM and 8 mM malonate at pH 7, isomerize to R-state crystals (Rpam,mal,soak), space group also P321 (a = 122.2 A, c = 156.4 A). The R-state structure in which the T----R transition occurs within the crystal at pH 7 compares very well (rms = 0.19 A for all atoms) with an R-state structure determined at pH 7 in which the crystals were initially grown in a solution of PAM and malonate at pH 5.9 and subsequently transferred to a buffer containing the ligands at pH 7 (Rpam,mal,crys). In fact, both of the PAM and malonate ligated R-state structures are very similar to both the carbamoyl phosphate and succinate or the N-(phosphonoacetyl)-L-aspartate ligated structures, even though the R-state structures reported here were determined at pH 7. Crystallographic residuals refined to 0.16-0.18 at 2.8-A resolution for the three structures.
About this Structure
3AT1 is a Protein complex structure of sequences from Escherichia coli with and as ligands. Active as Aspartate carbamoyltransferase, with EC number 2.1.3.2 Full crystallographic information is available from OCA.
Reference
Crystal structures of phosphonoacetamide ligated T and phosphonoacetamide and malonate ligated R states of aspartate carbamoyltransferase at 2.8-A resolution and neutral pH., Gouaux JE, Lipscomb WN, Biochemistry. 1990 Jan 16;29(2):389-402. PMID:2405902
Page seeded by OCA on Thu Feb 21 19:02:49 2008
