1dut
|
FIV DUTP PYROPHOSPHATASE
OverviewOverview
We have determined the crystal structure of dUTP pyrophosphatase (dUTPase), from feline immunodeficiency virus (FIV) at 1.9 A resolution. The, structure has been solved by the multiple isomorphous replacement (MIR), method using a P6(3) crystal form. The results show that the enzyme is a, trimer of 14.3 kDa subunits with marked structural similarity to E. coli, dUTPase. In both enzymes the C-terminal strand of an anti-parallel, beta-barrel participates in the beta-sheet of an adjacent subunit to form, an interdigitated, biologically functional trimer. In the P6(3) crystal, form one trimer packs on the 6(3) screw-axis and another on the threefold, axis so that there are two independent monomers per asymmetric unit. A, Mg2+ ion is coordinated by three asparate residues on the threefold axis, of each trimer. Alignment of 17 viral, prokaryotic, and eukaryotic dUTPase, sequences reveals five conserved motifs. Four of these map onto the, interface between pairs of subunits, defining a putative active site, region; the fifth resides in the C-terminal 16 residues, which is, disordered in the crystals. Conserved motifs from all three subunits are, required to create a given active site. With respect to viral protein, expression, it is particularly interesting that the gene for dUTPase (DU), resides in the middle of the Pol gene, the enzyme cassette of the, retroviral genome. Other enzymes encoded in the Pol polyprotein, including, protease (PR), reverse transcriptase (RT), and most likely integrase (IN), are dimeric enzymes, which implies that the stoichiometry of expression of, active trimeric dUTPase is distinct from the other Pol-encoded enzymes., Additionally, due to structural constraints, it is unlikely that dUTPase, can attain an active form prior to cleavage from the polyprotein.
About this StructureAbout this Structure
1DUT is a Single protein structure of sequence from Viruses with MG as ligand. Active as dUTP diphosphatase, with EC number 3.6.1.23 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of dUTP pyrophosphatase from feline immunodeficiency virus., Prasad GS, Stura EA, McRee DE, Laco GS, Hasselkus-Light C, Elder JH, Stout CD, Protein Sci. 1996 Dec;5(12):2429-37. PMID:8976551
Page seeded by OCA on Tue Nov 20 13:36:11 2007