1yrl
From Proteopedia
(New page: 200px<br /><applet load="1yrl" size="450" color="white" frame="true" align="right" spinBox="true" caption="1yrl, resolution 2.6Å" /> '''Escherichia coli keto...) |
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| - | [[Image:1yrl.gif|left|200px]]<br /><applet load="1yrl" size=" | + | [[Image:1yrl.gif|left|200px]]<br /><applet load="1yrl" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1yrl, resolution 2.6Å" /> | caption="1yrl, resolution 2.6Å" /> | ||
'''Escherichia coli ketol-acid reductoisomerase'''<br /> | '''Escherichia coli ketol-acid reductoisomerase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) catalyzes two steps in the | + | Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) catalyzes two steps in the biosynthesis of branched-chain amino acids. Amino acid sequence comparisons across species reveal that there are two types of this enzyme: a short form (Class I) found in fungi and most bacteria, and a long form (Class II) typical of plants. Crystal structures of each have been reported previously. However, some bacteria such as Escherichia coli possess a long form, where the amino acid sequence differs appreciably from that found in plants. Here, we report the crystal structure of the E. coli enzyme at 2.6 A resolution, the first three-dimensional structure of any bacterial Class II KARI. The enzyme consists of two domains, one with mixed alpha/beta structure, which is similar to that found in other pyridine nucleotide-dependent dehydrogenases. The second domain is mainly alpha-helical and shows strong evidence of internal duplication. Comparison of the active sites between KARI of E. coli, Pseudomonas aeruginosa, and spinach shows that most residues occupy conserved positions in the active site. E. coli KARI was crystallized as a tetramer, the likely biologically active unit. This contrasts with P. aeruginosa KARI, which forms a dodecamer, and spinach KARI, a dimer. In the E. coli KARI tetramer, a novel subunit-to-subunit interacting surface is formed by a symmetrical pair of bulbous protrusions. |
==About this Structure== | ==About this Structure== | ||
| - | 1YRL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ketol-acid_reductoisomerase Ketol-acid reductoisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.86 1.1.1.86] Full crystallographic information is available from [http:// | + | 1YRL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ketol-acid_reductoisomerase Ketol-acid reductoisomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.86 1.1.1.86] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YRL OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Ketol-acid reductoisomerase]] | [[Category: Ketol-acid reductoisomerase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Duggleby, R | + | [[Category: Duggleby, R G.]] |
[[Category: Duquerroy, S.]] | [[Category: Duquerroy, S.]] | ||
| - | [[Category: Guddat, L | + | [[Category: Guddat, L W.]] |
[[Category: Navaza, J.]] | [[Category: Navaza, J.]] | ||
[[Category: Tyagi, R.]] | [[Category: Tyagi, R.]] | ||
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[[Category: reductoisomerase]] | [[Category: reductoisomerase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:08:21 2008'' |
Revision as of 14:08, 21 February 2008
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Escherichia coli ketol-acid reductoisomerase
Overview
Ketol-acid reductoisomerase (KARI; EC 1.1.1.86) catalyzes two steps in the biosynthesis of branched-chain amino acids. Amino acid sequence comparisons across species reveal that there are two types of this enzyme: a short form (Class I) found in fungi and most bacteria, and a long form (Class II) typical of plants. Crystal structures of each have been reported previously. However, some bacteria such as Escherichia coli possess a long form, where the amino acid sequence differs appreciably from that found in plants. Here, we report the crystal structure of the E. coli enzyme at 2.6 A resolution, the first three-dimensional structure of any bacterial Class II KARI. The enzyme consists of two domains, one with mixed alpha/beta structure, which is similar to that found in other pyridine nucleotide-dependent dehydrogenases. The second domain is mainly alpha-helical and shows strong evidence of internal duplication. Comparison of the active sites between KARI of E. coli, Pseudomonas aeruginosa, and spinach shows that most residues occupy conserved positions in the active site. E. coli KARI was crystallized as a tetramer, the likely biologically active unit. This contrasts with P. aeruginosa KARI, which forms a dodecamer, and spinach KARI, a dimer. In the E. coli KARI tetramer, a novel subunit-to-subunit interacting surface is formed by a symmetrical pair of bulbous protrusions.
About this Structure
1YRL is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Ketol-acid reductoisomerase, with EC number 1.1.1.86 Full crystallographic information is available from OCA.
Reference
The crystal structure of a bacterial class II ketol-acid reductoisomerase: domain conservation and evolution., Tyagi R, Duquerroy S, Navaza J, Guddat LW, Duggleby RG, Protein Sci. 2005 Dec;14(12):3089-100. PMID:16322583
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