The Crystal Structure of 5'-deoxy-5'-methylthioadenosine Phosphorylase Ii from Sulfolobus Solfataricus, a Thermophilic Enzyme Stabilized by Intramolecular Disulfide Bonds.
From: Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-1301, USA.
Journal of molecular biology
- Publish Date: Mar 2006
- ISSN: 0022-2836
- Volume: 357
- Issue: 1
- Pages: 252-62
- Medium: Print
- Language: English
- Citation (JAMA): Zhang Yan, Porcelli Marina, Cacciapuoti Giovanna, et al. The Crystal Structure of 5'-deoxy-5'-methylthioadenosine Phosphorylase Ii from Sulfolobus Solfataricus, a Thermophilic Enzyme Stabilized by Intramolecular Disulfide Bonds.. J. Mol. Biol. Mar 2006;357:252-62
Abstract
The crystal structure of Sulfolobus solfataricus 5’-deoxy-5’-methylthioadenosine phosphorylase II (SsMTAPII) in complex with 5’-deoxy-5’-methylthioadenosine (MTA) and sulfate was determined to 1.45A resolution. The hexameric structure of SsMTAPII is a dimer-of-trimers with one active site per monomer. The oligomeric assembly of the trimer and the monomer topology of SsMTAPII are almost identical with trimeric human 5’-deoxy-5’-methylthioadenosine phosphorylase (hMTAP). SsMTAPII is the first reported hexameric member in the trimeric class of purine nucleoside phosphorylase (PNP) from Archaea. Unlike hMTAP, which is highly specific for MTA, SsMTAPII also accepts adenosine as a substrate. The residues at the active sites of SsMTAPII and hMTAP are almost identical. The broad substrate specificity of SsMTAPII may be due to the flexibility of the C-terminal loop. SsMTAPII is extremely thermoactive and thermostable. The three-dimensional structure of SsMTAPII suggests that the unique dimer-of-trimers quaternary structure, a CXC motif at the C terminus, and two pairs of intrasubunit disulfide bridges may play an important role in its thermal stability.
Mesh Headings (Keywords): Binding Sites, Crystallography, X-Ray, Deoxyadenosines, Disulfides, Enzyme Stability, Humans, Isoenzymes, Models, Molecular, Molecular Sequence Data, Molecular Structure, Protein Structure, Quaternary, Protein Subunits, Purine-Nucleoside Phosphorylase, Substrate Specificity, Sulfolobus solfataricus, Temperature, Thionucleosides
Check for Full Text / PubMed Unique Identifier (PMID): 16414070
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.