1dr8
From Proteopedia
(New page: 200px<br /><applet load="1dr8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1dr8, resolution 2.70Å" /> '''STRUCTURE OF MODIFIE...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1dr8.jpg|left|200px]]<br /><applet load="1dr8" size=" | + | [[Image:1dr8.jpg|left|200px]]<br /><applet load="1dr8" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1dr8, resolution 2.70Å" /> | caption="1dr8, resolution 2.70Å" /> | ||
'''STRUCTURE OF MODIFIED 3-ISOPROPYLMALATE DEHYDROGENASE AT THE C-TERMINUS, HD177'''<br /> | '''STRUCTURE OF MODIFIED 3-ISOPROPYLMALATE DEHYDROGENASE AT THE C-TERMINUS, HD177'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Thermal stability of the Thermus thermophilus isopropylmalate | + | Thermal stability of the Thermus thermophilus isopropylmalate dehydrogenase enzyme was substantially lost upon the deletion of three residues from the C-terminus. However, the stability was partly recovered by the addition of two, four and seven amino acid residues (called HD177, HD708 and HD711, respectively) to the C-terminal region of the truncated enzyme. Three structures of these mutant enzymes were determined by an X-ray diffraction method. All protein crystals belong to space group P2(1) and their structures were solved by a standard molecular replacement method where the original dimer structure of the A172L mutant was used as a search model. Thermal stability of these mutant enzymes is discussed based on the 3D structure with special attention to the width of the active-site groove and the minor groove, distortion of beta-sheet pillar structure and size of cavity in the domain-domain interface around the C-terminus. Our previous studies revealed that the thermal stability of isopropylmalate dehydrogenase increases when the active-site cleft is closed (the closed form). In the present study it is shown that the active-site cleft can be regulated by open-close movement of the minor groove located at the opposite side to the active-site groove on the same subunit, through a paperclip-like motion. |
==About this Structure== | ==About this Structure== | ||
| - | 1DR8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Active as [http://en.wikipedia.org/wiki/3-isopropylmalate_dehydrogenase 3-isopropylmalate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.85 1.1.1.85] Full crystallographic information is available from [http:// | + | 1DR8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Active as [http://en.wikipedia.org/wiki/3-isopropylmalate_dehydrogenase 3-isopropylmalate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.85 1.1.1.85] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DR8 OCA]. |
==Reference== | ==Reference== | ||
| Line 23: | Line 23: | ||
[[Category: paperclip motion]] | [[Category: paperclip motion]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:19:38 2008'' |
Revision as of 10:19, 21 February 2008
|
STRUCTURE OF MODIFIED 3-ISOPROPYLMALATE DEHYDROGENASE AT THE C-TERMINUS, HD177
Overview
Thermal stability of the Thermus thermophilus isopropylmalate dehydrogenase enzyme was substantially lost upon the deletion of three residues from the C-terminus. However, the stability was partly recovered by the addition of two, four and seven amino acid residues (called HD177, HD708 and HD711, respectively) to the C-terminal region of the truncated enzyme. Three structures of these mutant enzymes were determined by an X-ray diffraction method. All protein crystals belong to space group P2(1) and their structures were solved by a standard molecular replacement method where the original dimer structure of the A172L mutant was used as a search model. Thermal stability of these mutant enzymes is discussed based on the 3D structure with special attention to the width of the active-site groove and the minor groove, distortion of beta-sheet pillar structure and size of cavity in the domain-domain interface around the C-terminus. Our previous studies revealed that the thermal stability of isopropylmalate dehydrogenase increases when the active-site cleft is closed (the closed form). In the present study it is shown that the active-site cleft can be regulated by open-close movement of the minor groove located at the opposite side to the active-site groove on the same subunit, through a paperclip-like motion.
About this Structure
1DR8 is a Single protein structure of sequence from Thermus thermophilus. Active as 3-isopropylmalate dehydrogenase, with EC number 1.1.1.85 Full crystallographic information is available from OCA.
Reference
Crystal structures of 3-isopropylmalate dehydrogenases with mutations at the C-terminus: crystallographic analyses of structure-stability relationships., Nurachman Z, Akanuma S, Sato T, Oshima T, Tanaka N, Protein Eng. 2000 Apr;13(4):253-8. PMID:10810156
Page seeded by OCA on Thu Feb 21 12:19:38 2008
