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- ****************************************************
- * Ribonucleotide reductase small subunit signature *
- ****************************************************
-
- Ribonucleotide reductase (EC 1.17.4.1) [1,2] catalyzes the reductive synthesis
- of deoxyribonucleotides from their corresponding ribonucleotides. It provides
- the precursors necessary for DNA synthesis. Ribonucleotide reductase is an
- oligomeric enzyme composed of a large subunit (700 to 1000 residues) and a
- small subunit (300 to 400 residues).
-
- The small chain binds two iron atoms [3] (three Glu, one Asp, and two His are
- involved in metal binding) and contains an active site tyrosine radical. The
- regions of the sequence that contain the metal-binding residues and the active
- site tyrosine are conserved in ribonucleotide reductase small chain from
- prokaryotes, eukaryotes and viruses.
-
- We have selected one of these regions as a signature pattern. It contains the
- active site residue as well as a glutamate and a histidine involved in the
- binding of iron.
-
- -Consensus pattern: E-x-[LIVTA]-H-x(3)-Y-x(2)-[LIVQ]-x(3)-[LIVMFY](2)
- [E and H bind iron, Y is the active site residue]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: 3.
- -Last update: October 1993 / Text revised.
-
- [ 1] Nillson O., Lundqvist T., Hahne S., Sjoberg B.-M.
- Biochem. Soc. Trans. 16:91-94(1988).
- [ 2] Reichard P.
- Science 260:1773-1777(1993).
- [ 3] Nordlund P., Sjoberg B.-M., Eklund H.
- Nature 345:593-598(1990).
-