2R84

Crystal structure of PurP from Pyrococcus furiosus complexed with AMP and AICAR

Summary for 2R84

• Entry DOI: 10.2210/pdb2r84/pdb
• Related: 2R85 2R86 2R87
• Descriptor: PurP protein PF1517, SODIUM ION, CHLORIDE ION, ... (7 entities in total)
• Functional Keywords: atp-grasp superfamily, unknown function
• Biological source: Pyrococcus furiosus
• Total number of polymer chains: 2
• Total formula weight: 78538.57

Authors

Zhang, Y.,White, R.H.,Ealick, S.E. (deposition date: 2007-09-10, release date: 2007-12-04, Last modification date: 2023-08-30)

Primary citation

Zhang, Y.,White, R.H.,Ealick, S.E.
Crystal structure and function of 5-formaminoimidazole-4-carboxamide ribonucleotide synthetase from Methanocaldococcus jannaschii.
Biochemistry, 47:205-217, 2008

PubMed Abstract: Purine biosynthesis requires 10 enzymatic steps in higher organisms, while prokaryotes require an additional enzyme for step 6. In most organisms steps 9 and 10 are catalyzed by the purH gene product, a bifunctional enzyme with both 5-formaminoimidazole-4-carboxamide ribonucleotide (FAICAR) synthase and inosine monophosphate (IMP) cyclohydrolase activity. Recently it was discovered that Archaea utilize different enzymes to catalyze steps 9 and 10. An ATP-dependent FAICAR synthetase is encoded by the purP gene, and IMP cyclohydrolase is encoded by the purO gene. We have determined the X-ray crystal structures of FAICAR synthetase from Methanocaldococcus jannaschii complexed with various ligands, including the tertiary substrate complex and product complex. The enzyme belongs to the ATP grasp superfamily and is predicted to use a formyl phosphate intermediate formed by an ATP-dependent phosphorylation. In addition, we have determined the structures of a PurP orthologue from Pyrococcus furiosus, which is functionally unclassified, in three crystal forms. With approximately 50% sequence identity, P. furiosus PurP is structurally homologous to M. jannaschii PurP. A phylogenetic analysis was performed to explore the possible role of this functionally unclassified PurP.

PubMed: 18069798
DOI: 10.1021/bi701406g

Experimental method

X-RAY DIFFRACTION (1.9 Å)