1peu
From Proteopedia
(New page: 200px<br /><applet load="1peu" size="450" color="white" frame="true" align="right" spinBox="true" caption="1peu, resolution 3.20Å" /> '''Ribonucleotide Reduc...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1peu.jpg|left|200px]]<br /><applet load="1peu" size=" | + | [[Image:1peu.jpg|left|200px]]<br /><applet load="1peu" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1peu, resolution 3.20Å" /> | caption="1peu, resolution 3.20Å" /> | ||
'''Ribonucleotide Reductase Protein R1E from Salmonella typhimurium'''<br /> | '''Ribonucleotide Reductase Protein R1E from Salmonella typhimurium'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The three-dimensional structure of the large subunit of the first member | + | The three-dimensional structure of the large subunit of the first member of a class Ib ribonucleotide reductase, R1E of Salmonella typhimurium, has been determined in its native form and together with three allosteric effectors. The enzyme contains the characteristic ten-stranded alpha/beta-barrel with catalytic residues at a finger loop in its center and with redox-active cysteine residues at two adjacent barrel strands. Structures where the redox-active cysteine residues are in reduced thiol form and in oxidized disulfide form have been determined revealing local structural changes. The R1E enzyme differs from the class Ia enzyme, Escherichia coli R1, by not having an overall allosteric regulation. This is explained from the structure by differences in the N-terminal domain, which is about 50 residues shorter and lacks the overall allosteric binding site. R1E has an allosteric substrate specificity regulation site and the binding site for the nucleotide effectors is located at the dimer interface similarly as for the class Ia enzymes. We have determined the structures of R1E in the absence of effectors and with dTTP, dATP and dCTP bound. The low affinity for ATP at the specificity site is explained by a tyrosine, which hinders nucleotides containing a 2'-OH group to bind. |
==About this Structure== | ==About this Structure== | ||
| - | 1PEU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with MG and DTP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Full crystallographic information is available from [http:// | + | 1PEU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=DTP:'>DTP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PEU OCA]. |
==Reference== | ==Reference== | ||
| Line 26: | Line 26: | ||
[[Category: protein-specificity-effector complex]] | [[Category: protein-specificity-effector complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:28:12 2008'' |
Revision as of 12:28, 21 February 2008
|
Ribonucleotide Reductase Protein R1E from Salmonella typhimurium
Overview
The three-dimensional structure of the large subunit of the first member of a class Ib ribonucleotide reductase, R1E of Salmonella typhimurium, has been determined in its native form and together with three allosteric effectors. The enzyme contains the characteristic ten-stranded alpha/beta-barrel with catalytic residues at a finger loop in its center and with redox-active cysteine residues at two adjacent barrel strands. Structures where the redox-active cysteine residues are in reduced thiol form and in oxidized disulfide form have been determined revealing local structural changes. The R1E enzyme differs from the class Ia enzyme, Escherichia coli R1, by not having an overall allosteric regulation. This is explained from the structure by differences in the N-terminal domain, which is about 50 residues shorter and lacks the overall allosteric binding site. R1E has an allosteric substrate specificity regulation site and the binding site for the nucleotide effectors is located at the dimer interface similarly as for the class Ia enzymes. We have determined the structures of R1E in the absence of effectors and with dTTP, dATP and dCTP bound. The low affinity for ATP at the specificity site is explained by a tyrosine, which hinders nucleotides containing a 2'-OH group to bind.
About this Structure
1PEU is a Single protein structure of sequence from Salmonella typhimurium with and as ligands. Active as Ribonucleoside-diphosphate reductase, with EC number 1.17.4.1 Full crystallographic information is available from OCA.
Reference
Structure of the large subunit of class Ib ribonucleotide reductase from Salmonella typhimurium and its complexes with allosteric effectors., Uppsten M, Farnegardh M, Jordan A, Eliasson R, Eklund H, Uhlin U, J Mol Biol. 2003 Jun 27;330(1):87-97. PMID:12818204
Page seeded by OCA on Thu Feb 21 14:28:12 2008
