Abstract
The (β/α)8-barrel is one of the most common folds functioning as enzymes. The emergence of two (β/α)8-barrel enzymes involved in histidine biosynthesis, each of which has a twofold symmetric structure, has been proposed to be a consequence of tandem duplication and fusion of a (β/α)4-half-barrel. However, little evidence has been found for the existence of an ancestral half-barrel in the evolution of other (β/α)8-barrel proteins. In order to detect remnants of an ancestral half-barrel in the (β/α)8-barrel structure of Escherichia coli N-(5′-phosphoribosyl)anthranilate isomerase, we engineered three potential half-barrel units, (β/α)1-4, (β/α)3-6, and (β/α)5-8. Among these three arrangements, only (β/α)3-6 is stable; it exists in equilibrium between monomeric and dimeric forms. Thus, the central segment of N-(5′-phosphoribosyl)anthranilate isomerase from E. coli can serve as a half-barrel precursor. A tandem duplication of (β/α)3-6 yielded predominantly monomeric structures that were quite stable. This result exemplified that the structural characteristics of noncovalently assembled half-barrels could be improved by duplication and fusion. Moreover, our results may provide information regarding the local structural units that encompass interactions important for the early folding events of this ubiquitous protein conformation.
| Original language | English |
|---|---|
| Pages (from-to) | 458-466 |
| Number of pages | 9 |
| Journal | Journal of Molecular Biology |
| Volume | 382 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2008 Oct 3 |
| Externally published | Yes |
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Keywords
- (β/α)-barrel
- gene duplication
- half-barrel
- protein stability
- tryptophan biosynthetic enzyme
ASJC Scopus subject areas
- Virology
Cite this
Experimental Evidence for the Existence of a Stable Half-Barrel Subdomain in the (β/α)8-Barrel Fold. / Akanuma, Satoshi; Yamagishi, Akihiko.
In: Journal of Molecular Biology, Vol. 382, No. 2, 03.10.2008, p. 458-466.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Experimental Evidence for the Existence of a Stable Half-Barrel Subdomain in the (β/α)8-Barrel Fold
AU - Akanuma, Satoshi
AU - Yamagishi, Akihiko
PY - 2008/10/3
Y1 - 2008/10/3
N2 - The (β/α)8-barrel is one of the most common folds functioning as enzymes. The emergence of two (β/α)8-barrel enzymes involved in histidine biosynthesis, each of which has a twofold symmetric structure, has been proposed to be a consequence of tandem duplication and fusion of a (β/α)4-half-barrel. However, little evidence has been found for the existence of an ancestral half-barrel in the evolution of other (β/α)8-barrel proteins. In order to detect remnants of an ancestral half-barrel in the (β/α)8-barrel structure of Escherichia coli N-(5′-phosphoribosyl)anthranilate isomerase, we engineered three potential half-barrel units, (β/α)1-4, (β/α)3-6, and (β/α)5-8. Among these three arrangements, only (β/α)3-6 is stable; it exists in equilibrium between monomeric and dimeric forms. Thus, the central segment of N-(5′-phosphoribosyl)anthranilate isomerase from E. coli can serve as a half-barrel precursor. A tandem duplication of (β/α)3-6 yielded predominantly monomeric structures that were quite stable. This result exemplified that the structural characteristics of noncovalently assembled half-barrels could be improved by duplication and fusion. Moreover, our results may provide information regarding the local structural units that encompass interactions important for the early folding events of this ubiquitous protein conformation.
AB - The (β/α)8-barrel is one of the most common folds functioning as enzymes. The emergence of two (β/α)8-barrel enzymes involved in histidine biosynthesis, each of which has a twofold symmetric structure, has been proposed to be a consequence of tandem duplication and fusion of a (β/α)4-half-barrel. However, little evidence has been found for the existence of an ancestral half-barrel in the evolution of other (β/α)8-barrel proteins. In order to detect remnants of an ancestral half-barrel in the (β/α)8-barrel structure of Escherichia coli N-(5′-phosphoribosyl)anthranilate isomerase, we engineered three potential half-barrel units, (β/α)1-4, (β/α)3-6, and (β/α)5-8. Among these three arrangements, only (β/α)3-6 is stable; it exists in equilibrium between monomeric and dimeric forms. Thus, the central segment of N-(5′-phosphoribosyl)anthranilate isomerase from E. coli can serve as a half-barrel precursor. A tandem duplication of (β/α)3-6 yielded predominantly monomeric structures that were quite stable. This result exemplified that the structural characteristics of noncovalently assembled half-barrels could be improved by duplication and fusion. Moreover, our results may provide information regarding the local structural units that encompass interactions important for the early folding events of this ubiquitous protein conformation.
KW - (β/α)-barrel
KW - gene duplication
KW - half-barrel
KW - protein stability
KW - tryptophan biosynthetic enzyme
UR - http://www.scopus.com/inward/record.url?scp=50049096112&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=50049096112&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2008.07.040
DO - 10.1016/j.jmb.2008.07.040
M3 - Article
VL - 382
SP - 458
EP - 466
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 2
ER -