Annotation

Description

Orotate phosphoribosyltransferase (OPRTase) is involved in the de novo biosynthesis of pyrimidine nucleotides by catalyzing the Mg2+ dependent formation of orotidine 5‘-monophosphate (OMP), from which uridine 5‘-monophosphate is synthesized. Crystal structure of OPRTase from Bacillus anthracis str. 'Ames Ancestor' has been solved and refined to 1.75 Å resolution with a single copy of the protein per asymmetric unit. The structure resembles the structure of the OPRTase from Streptococcus mutans, which was used as a molecular replacement model. Crystal packing reveals that the B. anthracis OPRTase is a homodimer with a total buried surface area of 1950 Å. In the dimer, active site of each chain is at oligomerization interface. The residues Thr71 through Gly75 and Arg94 through Asn104 are structurally disordered.  

Functional assignment

Transferase 

Structure information

Unit cell parameters

Space Group

P 41 21 2  

Unit Cell

a=56.76Å, b=56.76Å, c=113.71Å
α=90.00, β=90.00, γ=90.00 

Solvent content

31.5  

Matthews coefficient

1.8  

Refinement

Data for the highest resolution shell is in parentheses.

Resolution range

28.43-1.75Å (1.80-1.75Å)  

R_all(%)

18.1 

R_work(%)

17.9 (18.2) 

R_free(%)

22.3 (24.1) 

Num. observed reflections

19350 (1400) 

Num. R_free reflections

986 (79) 

Completeness(%)

99.4 (100.0) 

Model parameters

Num Atoms

1642  

Num Waters

110  

Num Hetatoms

119  

Model mean isotropic B factor

19.590Ų  

RMSD bond length

0.010Å  

RMSD bond angle

1.280°  

Filename uploaded

3M3H.pdb (uploaded on Sep 17, 2010 7:06 PM)  

Inserted

Apr 05, 2010