Steve Ealick's Research Group
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Steve Ealick's Research Group |
Escherichia coli N5-carboxyaminoimidazole Ribonucleotide Mutase
PDB files:
1QCZ (native PurE)
1D7A (PurE complexed with AIR)
*2ATE (PurE complexed with nitro-AIR)
*2NSH, E. coli PurE H45Q mutant complexed with nitro-AIR
*2NSJ, E. coli PurE H45Q mutant complexed with CAIR
*2NSL, E. coli PurE H45N mutant complexed with CAIR
Description:
The crystal structure of PurE, which is the mutase that catalyzes the rearrangement
of N5-carboxyaminoimidazole ribonucleotide (N5-CAIR)
to 4-carboxyaminoimidazole
ribonucleotide (CAIR), has been determined to 1.50 Å and found to have
octameric structure. PurEs from higher eukaryotes are homologous to E.
coli PurE,
but use aminoimidazole ribonucleotide (AIR)and CO2 as substrates
to produce CAIR directly.
| A central three-layer (αβα) sandwich domain and a kinked C-terminal helix form the folded structure of the monomeric unit. The monomers are identical 17 kDa subunits |
Click the image to enlarge. |
| The monomers are arranged in an octameric structure with 422 symmetry. Here the octomer is viewed down the four-fold axis. |
Click the image to enlarge. |
| The left side of the graphic shows the wild type E. coli PurE active site bound to NO2-AIR, while the left site is the mutant H45Q EcPurE active site bound to CAIR. |
Click the image to enlarge. |
Reference:
Mathews II, Kappock TJ, Stubbe J and Ealick S. Crystal structure of Escherichia coli PurE, an unusual mutase in the purine biosynthetic pathway. Structure 7:1395-1406 (1999).
*Hoskins AA, Morar Mariya M, Kappock TJ, Mathews II, Zaugg JB, Barder TE, Peng P, Okamoto A, Ealick SE, and Stubbe J. N5-CAIR Mutase: the role of a CO2 binding site and substrate movement in catalysis. Biochemistry 46:2846-2855 (2007).
