J. Biol. Chem., Vol. 263, Issue 18, 8583-8591, 06, 1988
Structures of amidohydrolases. Amino acid sequence of a glutaminase- asparaginase from Acinetobacter glutaminasificans and preliminary crystallographic data for an asparaginase from Erwinia chrysanthemi
S Tanaka, EA Robinson, E Appella, M Miller, HL Ammon, J Roberts, IT Weber and A Wlodawer
Laboratory of Cell Biology, National Cancer Institute, Bethesda, Maryland 20205.
The complete amino acid sequence of a glutaminase-asparaginase from
Acinetobacter glutaminasificans, for which a preliminary tertiary structure
is available from crystallographic analysis, has been determined by
automated Edman degradation of fragments produced by chemical and
proteolytic cleavages. The protein consists of 331 amino acid residues and
has a molecular weight of 35,500. The pattern of hydrophilic and
hydrophobic regions is typical of a globular protein. A new crystal form of
an Erwinia chrysanthemi 1125 asparaginase is reported. The space group is
monoclinic C2, with unit cell parameters of: a = 107.8, b = 91.7, c = 129.2
A and beta = 91.7 degrees. A Vm of 2.25 A3/dalton was calculated for one
tetramer of 35,100-dalton subunits per asymmetric unit. X-ray intensity
data have been obtained to 2.2 A resolution. The point group symmetry of
the Er. chrysanthemi tetramer is 222 from self-rotation function
calculations. The relative orientations of an A. glutaminasificans
glutaminase-asparaginase model and the Er. chrysanthemi asparaginase
tetramer have been determined with the cross-rotation function, and
translation function calculations have revealed a plausible location for
the asparaginase tetramer in the crystal.