Hoecker, Birte and Claren, Jörg and Sterner, Reinhard (2004) Mimicking enzyme evolution by generating new (beta alpha)(8)-barrels from (beta alpha)(4)-half-barrels. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 101 (47). pp. 16448-16453. ISSN 0027-8424,
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Gene duplication and fusion events that multiply and link functional protein domains are crucial mechanisms of enzyme evolution. The analysis of amino acid sequences and three-dimensional structures suggested that the (betaalpha)(8)-barrel, which is the most frequent fold among enzymes, has evolved by the duplication, fusion, and mixing of (betaalpha)(4)-half-barrel domains. Here, we mimicked this evolutionary strategy by generating in vitro (betaalpha)(8)-barrels from (betaalpha)(4)-half-barrels that were deduced from the enzymes imidazole glycerol phosphate synthase (HisF) and N'[(5'-phosphoribosyl)formimino]-5-aminoimidazole-4-carboxamide-ribonucleotide isomerase (HisA). To this end, the gene for the C-terminal (betaalpha)(4)-half-barrel (HisF-C) of HisF was duplicated and fused in tandem to yield HisF-CC, which is more stable than HisF-C. In the next step, by optimizing side-chain interactions within the center of the beta-barrel of HisF-CC, the monomeric and compact (betaalpha)(8)-barrel protein HisF-C*C was generated. Moreover, the genes for the N- and C-terminal (betaalpha)(4)-half-barrels of HisF and HisA were fused crosswise to yield the chimeric proteins HisFA and HisAF. Whereas HisFA contains native secondary structure elements but adopts ill-defined association states, the (betaalpha)(8)-barrel HisAF is a stable and compact monomer that reversibly unfolds with high cooperativity. The results obtained suggest a previously undescribed dimension for the diversification of enzymatic activities: new (betaalpha)(8)-barrels with novel functions might have evolved by the exchange of (betaalpha)(4)-half-barrel domains with distinct functional properties.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | DIFFERENT METABOLIC PATHWAYS; DIVERGENT EVOLUTION; STRUCTURAL EVIDENCE; PROTEIN; STABILITY; BARREL; FOLD; HISTIDINE; SEQUENCES; FUSION; chimeric proteins; gene duplication; histidine biosynthesis; TIM-barrel |
| Subjects: | 500 Science > 570 Life sciences |
| Divisions: | Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Reinhard Sterner |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 21 Jun 2021 12:52 |
| Last Modified: | 21 Jun 2021 12:52 |
| URI: | https://pred.uni-regensburg.de/id/eprint/36946 |
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