The first structure of UDP-glucose dehydrogenase reveals the catalytic residues necessary for the two-fold oxidation
| Autor: | R E, Campbell, S C, Mosimann, I, van De Rijn, M E, Tanner, N C, Strynadka |
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| Rok vydání: | 2000 |
| Předmět: |
Models
Molecular Binding Sites Protein Conformation Streptococcus pyogenes Molecular Sequence Data Hydrogen Bonding Crystallography X-Ray NAD Uridine Diphosphate Glucose Dehydrogenase Protein Structure Tertiary Uridine Diphosphate Xylose Bacterial Proteins Uridine Diphosphate Glucuronic Acid Amino Acid Sequence Dimerization Sequence Alignment |
| Zdroj: | Biochemistry. 39(23) |
| ISSN: | 0006-2960 |
| Popis: | Bacterial UDP-glucose dehydrogenase (UDPGlcDH) is essential for formation of the antiphagocytic capsule that protects many virulent bacteria such as Streptococcus pyogenes andStreptococcus pneumoniae type 3 from the host's immune system. We have determined the X-ray structures of both native and Cys260Ser UDPGlcDH from S. pyogenes (74% similarity to S. pneumoniae) in ternary complexes with UDP-xylose/NAD(+) and UDP-glucuronic acid/NAD(H), respectively. The 402 residue homodimeric UDPGlcDH is composed of an N-terminal NAD(+) dinucleotide binding domain and a C-terminal UDP-sugar binding domain connected by a long (48 A) central alpha-helix. The first 290 residues of UDPGlcDH share structural homology with 6-phosphogluconate dehydrogenase, including conservation of an active site lysine and asparagine that are implicated in the enzyme mechanism. Also proposed to participate in the catalytic mechanism are a threonine and a glutamate that hydrogen bond to a conserved active site water molecule suitably positioned for general acid/base catalysis. |
| Databáze: | OpenAIRE |
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