Download MendeleyCrystal structure of a human mitochondrial deoxyribonucleotidase.
Rinaldo-Matthis, A., Rampazzo, C., Reichard, P., Bianchi, V., Nordlund, P.(2002) Nat Struct Biol 9: 779-787
- PubMed: 12352955
- DOI: https://doi.org/10.1038/nsb846
- Primary Citation of Related Structures:
1MH9 - PubMed Abstract:
5' nucleotidases are ubiquitous enzymes that dephosphorylate nucleoside monophosphates and participate in the regulation of nucleotide pools. The mitochondrial 5'-(3') deoxyribonucleotidase (dNT-2) specifically dephosphorylates dUMP and dTMP, thereby protecting mitochondrial DNA replication from excess dTTP. We have solved the structure of dNT-2, the first of a mammalian 5' nucleotidase. The structure reveals a relationship to the HAD family, members of which use an aspartyl nucleophile as their common catalytic strategy, with a phosphoserine phosphatase as the most similar neighbor. A structure-based sequence alignment of dNT-2 with other 5' nucleotidases also suggests a common origin for these enzymes. Here we study the structures of dNT-2 in complex with bound phosphate and beryllium trifluoride plus thymidine as model for a phosphoenzyme-product complex. Based on these structures, determinants for substrate specificity recognition and the catalytic action of dNT-2 are outlined.
Organizational Affiliation:
Department of Biochemistry and Biophysics, Stockholm University, S-106 91 Stockholm, Sweden.
