Three-dimensional Structure of a New Enzyme, O-Phosphoserine Sulfhydrylase, Involved in l-Cysteine Biosynthesis by a Hyperthermophilic Archaeon, Aeropyrum pernix K1, at 2.0Å Resolution
| Autor: | Yutaka Oda, Kazuhiko Ishikawa, Mitsuo Ataka, Koshiki Mino |
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| Rok vydání: | 2005 |
| Předmět: |
Models
Molecular Salmonella typhimurium Protein Conformation Dimer Carbon-Oxygen Lyases Molecular Sequence Data Cystathionine beta-Synthase O-phosphoserine sulfhydrylase Arginine Crystallography X-Ray Catalysis Protein Structure Secondary Cofactor Serine chemistry.chemical_compound Structural Biology Humans Aeropyrum pernix Amino Acid Sequence Cysteine Molecular Biology chemistry.chemical_classification Binding Sites Sequence Homology Amino Acid biology Active site Aeropyrum biology.organism_classification Protein Structure Tertiary Crystallography Enzyme chemistry Spectrophotometry Mutation Mutagenesis Site-Directed biology.protein Dimerization Protein Binding |
| Zdroj: | Journal of Molecular Biology. 351:334-344 |
| ISSN: | 0022-2836 |
| DOI: | 10.1016/j.jmb.2005.05.064 |
| Popis: | O-Phosphoserine sulfhydrylase is a new enzyme found in a hyperthermophilic archaeon, Aeropyrum pernix K1. This enzyme catalyzes a novel cysteine synthetic reaction from O-phospho-l-serine and sulfide. The crystal structure of the enzyme was determined at 2.0A resolution using the method of multi-wavelength anomalous dispersion. A monomer consists of three domains, including an N-terminal domain with a new alpha/beta fold. The topology folds of the middle and C-terminal domains were similar to those of the O-acetylserine sulfhydrylase-A from Salmonella typhimurium and the cystathionine beta-synthase from human. The cofactor, pyridoxal 5'-phosphate, is bound in a cleft between the middle and C-terminal domains through a covalent linkage to Lys127. Based on the structure determined, O-phospho-l-serine could be rationally modeled into the active site of the enzyme. An enzyme-substrate complex model and a mutation experiment revealed that Arg297, unique to hyperthermophilic archaea, is one of the most crucial residues for O-phosphoserine sulfhydrylation activity. There are more hydrophobic areas and less electric charges at the dimer interface, compared to the S.typhimurium O-acetylserine sulfhydrylase. |
| Databáze: | OpenAIRE |
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