1q95
From Proteopedia
(New page: 200px<br /><applet load="1q95" size="450" color="white" frame="true" align="right" spinBox="true" caption="1q95, resolution 2.46Å" /> '''Aspartate Transcarba...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1q95.gif|left|200px]]<br /><applet load="1q95" size=" | + | [[Image:1q95.gif|left|200px]]<br /><applet load="1q95" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1q95, resolution 2.46Å" /> | caption="1q95, resolution 2.46Å" /> | ||
'''Aspartate Transcarbamylase (ATCase) of Escherichia coli: A New Crystalline R State Bound to PALA, or to Product Analogues Phosphate and Citrate'''<br /> | '''Aspartate Transcarbamylase (ATCase) of Escherichia coli: A New Crystalline R State Bound to PALA, or to Product Analogues Phosphate and Citrate'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Structures of the R-state of Escherichia coli ATCase maintained with | + | Structures of the R-state of Escherichia coli ATCase maintained with carbamyl phosphate and succinate, phosphonoacetamide and malonate, or N-phosphonacetyl-l-aspartate (PALA) have previously been made in the space group P321, in which the two independent r (regulatory) and two independent c (catalytic) chains are repeated by crystallographic symmetry to yield the holoenzyme c(6)r(6), ((c(3))(2)(r(2))(3)). The exploration of a new crystalline R-state P2(1)2(1)2(1) was undertaken to examine the c(3).c(3) expansion of 11 A in the T-to-R transition, and to further test whether intermolecular contacts influence the binding of PALA. The results show that the expansion along the 3-fold axis is 10 A, and that the binding modes of the six crystallographic independent PALA molecules are virtually identical to one another, and to modes described previously. As further test, the PALA, a bisubstrate analogue, was displaced by citrate and phosphate, where citrate is an analogue of product carbamylaspartate. The results support the conclusions about the binding of the three previously studied analogues, and further support, within about 0.5 A, the structure proposed for the transition state [Gouaux, J. E., Krause, K. L., and Lipscomb, W. N. (1987) Biochem. Biophys. Res. Commun. 142, 893-897; Jin, L., Stec, B., Lipscomb, W. N., and Kantrowitz, E. R. (1999) Proteins: Struct., Funct., Genet. 37, 729-742]. |
==About this Structure== | ==About this Structure== | ||
| - | 1Q95 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 PAL 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:// | + | 1Q95 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=PAL:'>PAL</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=1Q95 OCA]. |
==Reference== | ==Reference== | ||
| Line 15: | Line 15: | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Huang, J.]] | [[Category: Huang, J.]] | ||
| - | [[Category: Lipscomb, W | + | [[Category: Lipscomb, W N.]] |
[[Category: PAL]] | [[Category: PAL]] | ||
[[Category: ZN]] | [[Category: ZN]] | ||
| Line 25: | Line 25: | ||
[[Category: r state]] | [[Category: r state]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:37:11 2008'' |
Revision as of 12:37, 21 February 2008
|
Aspartate Transcarbamylase (ATCase) of Escherichia coli: A New Crystalline R State Bound to PALA, or to Product Analogues Phosphate and Citrate
Overview
Structures of the R-state of Escherichia coli ATCase maintained with carbamyl phosphate and succinate, phosphonoacetamide and malonate, or N-phosphonacetyl-l-aspartate (PALA) have previously been made in the space group P321, in which the two independent r (regulatory) and two independent c (catalytic) chains are repeated by crystallographic symmetry to yield the holoenzyme c(6)r(6), ((c(3))(2)(r(2))(3)). The exploration of a new crystalline R-state P2(1)2(1)2(1) was undertaken to examine the c(3).c(3) expansion of 11 A in the T-to-R transition, and to further test whether intermolecular contacts influence the binding of PALA. The results show that the expansion along the 3-fold axis is 10 A, and that the binding modes of the six crystallographic independent PALA molecules are virtually identical to one another, and to modes described previously. As further test, the PALA, a bisubstrate analogue, was displaced by citrate and phosphate, where citrate is an analogue of product carbamylaspartate. The results support the conclusions about the binding of the three previously studied analogues, and further support, within about 0.5 A, the structure proposed for the transition state [Gouaux, J. E., Krause, K. L., and Lipscomb, W. N. (1987) Biochem. Biophys. Res. Commun. 142, 893-897; Jin, L., Stec, B., Lipscomb, W. N., and Kantrowitz, E. R. (1999) Proteins: Struct., Funct., Genet. 37, 729-742].
About this Structure
1Q95 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
Aspartate transcarbamylase (ATCase) of Escherichia coli: a new crystalline R-state bound to PALA, or to product analogues citrate and phosphate., Huang J, Lipscomb WN, Biochemistry. 2004 Jun 1;43(21):6415-21. PMID:15157075
Page seeded by OCA on Thu Feb 21 14:37:11 2008
