X-ray Structure of the Complete ABC Enzyme ABCE1 from Pyrococcus abyssi
| Autor: | Alexandra Schele, Annette Karcher, Karl-Peter Hopfner |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Pyrococcus abyssi
Archaeal Proteins Iron Ribosome biogenesis ATP-binding cassette transporter Crystallography X-Ray Biochemistry Protein structure Humans Magnesium Nucleotide Molecular Biology chemistry.chemical_classification biology Cell Biology biology.organism_classification Protein Structure Tertiary Adenosine Diphosphate ABCE1 chemistry Structural Homology Protein Cyclic nucleotide-binding domain biology.protein Ferredoxins ATP-Binding Cassette Transporters Oxidation-Reduction Sulfur Ribonuclease L |
| Zdroj: | Journal of Biological Chemistry. 283:7962-7971 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m707347200 |
| Popis: | The ATP binding cassette enzyme ABCE1 (also known as RNase-L (ribonuclease L) inhibitor, Pixie, and HP68), one of the evolutionary most sequence-conserved enzymes, functions in translation initiation, ribosome biogenesis, and human immunodeficiency virus capsid assembly. However, its structural mechanism and biochemical role in these processes have not been revealed. We determined the crystal structure of Pyrococcus abyssi ABCE1 in complex with Mg(2+) and ADP to 2.8A resolution. ABCE1 consists of four structural domains. Two nucleotide binding domains are arranged in a head-to-tail orientation by a hinge domain, suggesting that these domains undergo the characteristic tweezers-like powerstroke of ABC enzymes. In contrast to all other known ABC enzymes, ABCE1 has a N-terminal iron-sulfur-cluster (FeS) domain. The FeS domain contains two [4Fe-4S] clusters and is structurally highly related to bacterial-type ferredoxins. However, one cluster is coordinated by an unusual CX(4)CX(3/4)C triad. Surprisingly, intimate interactions of the FeS domain with the adenine and ribose binding Y-loop on nucleotide binding domain 1 suggest a linkage between FeS domain function and ATP-induced conformational control of the ABC tandem cassette. The structure substantially expands the functional architecture of ABC enzymes and raises the possibility that ABCE1 is a chemomechanical engine linked to a redox process. |
| Databáze: | OpenAIRE |
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