|
|
| Line 1: |
Line 1: |
| [[Image:1tth.gif|left|200px]] | | {{Seed}} |
| | [[Image:1tth.png|left|200px]] |
|
| |
|
| <!-- | | <!-- |
| Line 9: |
Line 10: |
| {{STRUCTURE_1tth| PDB=1tth | SCENE= }} | | {{STRUCTURE_1tth| PDB=1tth | SCENE= }} |
|
| |
|
| '''Aspartate Transcarbamoylase Catalytic Chain Mutant Glu50Ala Complexed with N-(Phosphonacetyl-L-Aspartate) (PALA)'''
| | ===Aspartate Transcarbamoylase Catalytic Chain Mutant Glu50Ala Complexed with N-(Phosphonacetyl-L-Aspartate) (PALA)=== |
|
| |
|
|
| |
|
| ==Overview==
| | <!-- |
| A detailed description of the transition that allosteric enzymes undergo constitutes a major challenge in structural biology. We have succeeded in trapping four distinct allosteric states of a mutant enzyme of Escherichia coli aspartate transcarbomylase and determining their structures by X-ray crystallography. The mutant version of aspartate transcarbamoylase in which Glu50 in the catalytic chains was replaced by Ala destabilizes the native R state and shifts the equilibrium towards the T state. This behavior allowed the use of substrate analogs such as phosphonoacetamide and malonate to trap the enzyme in T-like and R-like structures that are distinct from the T-state structure of the wild-type enzyme (as represented by the structure of the enzyme with CTP bound and the R-state structure as represented by the structure with N-(phosphonacetyl)-L-aspartate bound). These structures shed light on the nature and the order of internal structural rearrangements during the transition from the T to the R state. They also suggest an explanation for diminished activity of the E50A enzyme and for the change in reaction mechanism from ordered to random for this mutant enzyme.
| | The line below this paragraph, {{ABSTRACT_PUBMED_15288791}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 15288791 is the PubMed ID number. |
| | --> |
| | {{ABSTRACT_PUBMED_15288791}} |
|
| |
|
| ==About this Structure== | | ==About this Structure== |
| Line 30: |
Line 34: |
| [[Category: Domain closure]] | | [[Category: Domain closure]] |
| [[Category: Site-specific mutagenesis]] | | [[Category: Site-specific mutagenesis]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 10:20:40 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 07:39:06 2008'' |
