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1tht
From Proteopedia
(New page: 200px<br /><applet load="1tht" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tht, resolution 2.1Å" /> '''STRUCTURE OF A MYRIST...) |
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| - | [[Image:1tht.jpg|left|200px]]<br /><applet load="1tht" size=" | + | [[Image:1tht.jpg|left|200px]]<br /><applet load="1tht" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1tht, resolution 2.1Å" /> | caption="1tht, resolution 2.1Å" /> | ||
'''STRUCTURE OF A MYRISTOYL-ACP-SPECIFIC THIOESTERASE FROM VIBRIO HARVEYI'''<br /> | '''STRUCTURE OF A MYRISTOYL-ACP-SPECIFIC THIOESTERASE FROM VIBRIO HARVEYI'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of a myristoyl acyl carrier protein specific | + | The crystal structure of a myristoyl acyl carrier protein specific thioesterase (C14ACP-TE) from a bioluminescent bacterium, Vibrio harveyi, was solved by multiple isomorphous replacement methods and refined to an R factor of 22% at 2.1-A resolution. This is the first elucidation of a three-dimensional structure of a thioesterase. The overall tertiary architecture of the enzyme resembles closely the consensus fold of the rapidly expanding superfamily of alpha/beta hydrolases, although there is no detectable homology with any of its members at the amino acid sequence level. Particularly striking similarity exists between the C14ACP-TE structure and that of haloalkane dehalogenase from Xanthobacter autotrophicus. Contrary to the conclusions of earlier studies [Ferri, S. R., & Meighen, E. A. (1991) J. Biol. Chem. 266, 12852-12857] which implicated Ser77 in catalysis, the crystal structure of C14ACP-TE reveals a lipase-like catalytic triad made up of Ser114, His241, and Asp211. Surprisingly, the gamma-turn with Ser114 in a strained secondary conformation (phi = 53 degrees, psi = -127 degrees), characteristic of the so-called nucleophilic elbow, does not conform to the frequently invoked lipase/esterase consensus sequence (Gly-X-Ser-X-Gly), as the positions of both glycines are occupied by larger amino acids. Site-directed mutagenesis and radioactive labeling support the catalytic function of Ser114. Crystallographic analysis of the Ser77-->Gly mutant at 2.5-A resolution revealed no structural changes; in both cases the loop containing the residue in position 77 is disordered.(ABSTRACT TRUNCATED AT 250 WORDS) |
==About this Structure== | ==About this Structure== | ||
| - | 1THT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_harveyi Vibrio harveyi]. Full crystallographic information is available from [http:// | + | 1THT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_harveyi Vibrio harveyi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1THT OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Vibrio harveyi]] | [[Category: Vibrio harveyi]] | ||
[[Category: Derewenda, U.]] | [[Category: Derewenda, U.]] | ||
| - | [[Category: Derewenda, Z | + | [[Category: Derewenda, Z S.]] |
[[Category: Ferri, S.]] | [[Category: Ferri, S.]] | ||
| - | [[Category: Lawson, D | + | [[Category: Lawson, D M.]] |
| - | [[Category: Meighen, E | + | [[Category: Meighen, E A.]] |
[[Category: Serre, L.]] | [[Category: Serre, L.]] | ||
[[Category: Szitter, R.]] | [[Category: Szitter, R.]] | ||
| Line 23: | Line 23: | ||
[[Category: thioesterase]] | [[Category: thioesterase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:13:45 2008'' |
Revision as of 13:13, 21 February 2008
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STRUCTURE OF A MYRISTOYL-ACP-SPECIFIC THIOESTERASE FROM VIBRIO HARVEYI
Overview
The crystal structure of a myristoyl acyl carrier protein specific thioesterase (C14ACP-TE) from a bioluminescent bacterium, Vibrio harveyi, was solved by multiple isomorphous replacement methods and refined to an R factor of 22% at 2.1-A resolution. This is the first elucidation of a three-dimensional structure of a thioesterase. The overall tertiary architecture of the enzyme resembles closely the consensus fold of the rapidly expanding superfamily of alpha/beta hydrolases, although there is no detectable homology with any of its members at the amino acid sequence level. Particularly striking similarity exists between the C14ACP-TE structure and that of haloalkane dehalogenase from Xanthobacter autotrophicus. Contrary to the conclusions of earlier studies [Ferri, S. R., & Meighen, E. A. (1991) J. Biol. Chem. 266, 12852-12857] which implicated Ser77 in catalysis, the crystal structure of C14ACP-TE reveals a lipase-like catalytic triad made up of Ser114, His241, and Asp211. Surprisingly, the gamma-turn with Ser114 in a strained secondary conformation (phi = 53 degrees, psi = -127 degrees), characteristic of the so-called nucleophilic elbow, does not conform to the frequently invoked lipase/esterase consensus sequence (Gly-X-Ser-X-Gly), as the positions of both glycines are occupied by larger amino acids. Site-directed mutagenesis and radioactive labeling support the catalytic function of Ser114. Crystallographic analysis of the Ser77-->Gly mutant at 2.5-A resolution revealed no structural changes; in both cases the loop containing the residue in position 77 is disordered.(ABSTRACT TRUNCATED AT 250 WORDS)
About this Structure
1THT is a Single protein structure of sequence from Vibrio harveyi. Full crystallographic information is available from OCA.
Reference
Structure of a myristoyl-ACP-specific thioesterase from Vibrio harveyi., Lawson DM, Derewenda U, Serre L, Ferri S, Szittner R, Wei Y, Meighen EA, Derewenda ZS, Biochemistry. 1994 Aug 16;33(32):9382-8. PMID:8068614
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