2bq1: Difference between revisions
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==Overview== | ==Overview== | ||
Ribonucleotide reductase is an indispensable enzyme for all cells, since, it catalyses the biosynthesis of the precursors necessary for both, building and repairing DNA. The ribonucleotide reductase class I enzymes, present in all mammals as well as in many prokaryotes and DNA viruses, are, composed mostly of two homodimeric proteins, R1 and R2. The reaction, involves long-range radical transfer between the two proteins. Here, we, present the first crystal structure of a ribonucleotide reductase R1/R2, holocomplex. The biological relevance of this complex is based on the, binding of the R2 C terminus in the hydrophobic cleft of R1, an, interaction proven to be crucial for enzyme activity, and by the fact that, all conserved amino acid residues in R2 are facing the R1 active sites. We, | Ribonucleotide reductase is an indispensable enzyme for all cells, since, it catalyses the biosynthesis of the precursors necessary for both, building and repairing DNA. The ribonucleotide reductase class I enzymes, present in all mammals as well as in many prokaryotes and DNA viruses, are, composed mostly of two homodimeric proteins, R1 and R2. The reaction, involves long-range radical transfer between the two proteins. Here, we, present the first crystal structure of a ribonucleotide reductase R1/R2, holocomplex. The biological relevance of this complex is based on the, binding of the R2 C terminus in the hydrophobic cleft of R1, an, interaction proven to be crucial for enzyme activity, and by the fact that, all conserved amino acid residues in R2 are facing the R1 active sites. We, suggest that the asymmetric R1/R2 complex observed in the 4A crystal, structure of Salmonella typhimurium ribonucleotide reductase represents an, intermediate stage in the reaction cycle, and at the moment of reaction, the homodimers transiently form a tight symmetric complex. | ||
==About this Structure== | ==About this Structure== | ||
2BQ1 is a | 2BQ1 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with MG, FE and DGT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribonucleoside-diphosphate_reductase Ribonucleoside-diphosphate reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.4.1 1.17.4.1] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BQ1 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: ribonucleotide reductase]] | [[Category: ribonucleotide reductase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:21:50 2007'' | ||
