2r84

From Proteopedia

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

Structural highlights

2r84 is a 2 chain structure with sequence from Pyrococcus furiosus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 1.9Å
Ligands:	, , , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PURP_PYRFU Catalyzes the ATP- and formate-dependent formylation of 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranosyl 5'-monophosphate (AICAR) to 5-formaminoimidazole-4-carboxamide-1-beta-d-ribofuranosyl 5'-monophosphate (FAICAR) in the absence of folates.[HAMAP-Rule:MF_01163]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

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.

Crystal structure and function of 5-formaminoimidazole-4-carboxamide ribonucleotide synthetase from Methanocaldococcus jannaschii.,Zhang Y, White RH, Ealick SE Biochemistry. 2008 Jan 8;47(1):205-17. Epub 2007 Dec 11. PMID:18069798^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Zhang Y, White RH, Ealick SE. Crystal structure and function of 5-formaminoimidazole-4-carboxamide ribonucleotide synthetase from Methanocaldococcus jannaschii. Biochemistry. 2008 Jan 8;47(1):205-17. Epub 2007 Dec 11. PMID:18069798 doi:10.1021/bi701406g