Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å
碩士 === 國立清華大學 === 生命科學系 === 91 === The members of the enolase superfamily sharing the common ability to catalyze abstraction of the α-proton of carboxylic acids. Although each reaction catalyzed by these enzymes is initiated by this common step, their overall reactions as well as the stereochemical...
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ndltd-TW-091NTHU01050362016-06-22T04:21:08Z http://ndltd.ncl.edu.tw/handle/72271613918501336617 Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å DeinococcusradioduransN醯化胺基酸消旋酶1.3Å的晶體結構 Chun-Li Wu 吳峻岦 碩士 國立清華大學 生命科學系 91 The members of the enolase superfamily sharing the common ability to catalyze abstraction of the α-proton of carboxylic acids. Although each reaction catalyzed by these enzymes is initiated by this common step, their overall reactions as well as the stereochemical consequences of the β-elimination reactions are diverse. A protein identified as “N-acylamino acid racemase”, a member of enolase superfamily, racemizes optically active N-acylamino acid in the presence of optical active amino acid; its use in combination with D- or L-aminoacylase enables the production of optically active D- or L-alpha-amino acid from DL-acyl-alpha-aminocarboxylic acid at a high level of efficiency. N-acylamino acid racemase from Amycolaptosis sp. is an inefficient enzyme(kcat/Km=3.7×102 M-1 s-1). Its sequence is 43% identical to that of an unidentified protein encoded by the Bacillus subtilis genome. Both proteins efficiently catalyze the o-succinylbenzoate synthase reaction in menaquinone biosynthesis(kcat/Km=2.5×105 and 7.5×105 M-1 s-1, respectively), suggesting that this is their “correct” metabolic function. We have solved the X-ray structure of N-acylamino acid racemase from Deinococcus radiodurans to 1.3Å resolution by multiple wavelength anomalous diffraction(MAD). The two-domanins fold found for N-acylamino acid racemase is similar to those for other members of the enolase superfamily:a mixed α/β capping domain formed from segments at the N- and C-termini of the polypeptide and a larger(β/α)7β barrel domain. We have compared the structure with o-succinylbenzoate synthase, and speculated that Lys168,Lys170,Asp195,Glu220,Asp245,Lys269 are the key residues in the catalytic region. As a result, evolution of both the shape and volume of the active site should be subject to few structural constraints. This would provide a structural strategy for the evolution of new catalytic activities in homologues of enolase superfamily and a likely explanation for how the o-succinylbenzoate synthase from Amycolaptosis sp. also can catalyze the reaction of N-acylamino acid racemase(Palmer et al., 1999; Thomas et al., 2000; Andrew et al., 2001). W.C. Wang 王雯靜 2001 學位論文 ; thesis 80 zh-TW |
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碩士 === 國立清華大學 === 生命科學系 === 91 === The members of the enolase superfamily sharing the common ability to catalyze abstraction of the α-proton of carboxylic acids. Although each reaction catalyzed by these enzymes is initiated by this common step, their overall reactions as well as the stereochemical consequences of the β-elimination reactions are diverse. A protein identified as “N-acylamino acid racemase”, a member of enolase superfamily, racemizes optically active N-acylamino acid in the presence of optical active amino acid; its use in combination with D- or L-aminoacylase enables the production of optically active D- or L-alpha-amino acid from DL-acyl-alpha-aminocarboxylic acid at a high level of efficiency. N-acylamino acid racemase from Amycolaptosis sp. is an inefficient enzyme(kcat/Km=3.7×102 M-1 s-1). Its sequence is 43% identical to that of an unidentified protein encoded by the Bacillus subtilis genome. Both proteins efficiently catalyze the o-succinylbenzoate synthase reaction in menaquinone biosynthesis(kcat/Km=2.5×105 and 7.5×105 M-1 s-1, respectively), suggesting that this is their “correct” metabolic function. We have solved the X-ray structure of N-acylamino acid racemase from Deinococcus radiodurans to 1.3Å resolution by multiple wavelength anomalous diffraction(MAD). The two-domanins fold found for N-acylamino acid racemase is similar to those for other members of the enolase superfamily:a mixed α/β capping domain formed from segments at the N- and C-termini of the polypeptide and a larger(β/α)7β barrel domain. We have compared the structure with o-succinylbenzoate synthase, and speculated that Lys168,Lys170,Asp195,Glu220,Asp245,Lys269 are the key residues in the catalytic region. As a result, evolution of both the shape and volume of the active site should be subject to few structural constraints. This would provide a structural strategy for the evolution of new catalytic activities in homologues of enolase superfamily and a likely explanation for how the o-succinylbenzoate synthase from Amycolaptosis sp. also can catalyze the reaction of N-acylamino acid racemase(Palmer et al., 1999; Thomas et al., 2000; Andrew et al., 2001).
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author2 |
W.C. Wang |
author_facet |
W.C. Wang Chun-Li Wu 吳峻岦 |
author |
Chun-Li Wu 吳峻岦 |
spellingShingle |
Chun-Li Wu 吳峻岦 Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å |
author_sort |
Chun-Li Wu |
title |
Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å |
title_short |
Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å |
title_full |
Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å |
title_fullStr |
Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å |
title_full_unstemmed |
Crystal structure of Deinococcus radiodurans N-acylamino acid racemase at 1.3Å |
title_sort |
crystal structure of deinococcus radiodurans n-acylamino acid racemase at 1.3å |
publishDate |
2001 |
url |
http://ndltd.ncl.edu.tw/handle/72271613918501336617 |
work_keys_str_mv |
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