Polymorphous crystallization and diffraction of threonine deaminase from Escherichia coli

Abstract

The biosynthetic thrconine deaminase from Escherichia coli, an allosteric tetramer with key regulatory functions, has been crystallized in several crystal forms. Two distinct forms, both belonging to either space group P3~21 or P3221, with different sized asymmetric units that both contain a tetramer, grow under identical conditions. Diffraction data sets to 2.8 A resolution (native) and 2.9 ,~, resolution (isomorphous uranyl derivative) have been collected from a third crystal form in space group 1222.

Structure and control of pyridoxal phosphate dependent allosteric threonine deaminase

“…TD was prepared as described previously [13,15] and crystallization, diffraction at pH 7.2 and data processing were as described in [19]. Single isomorphous replacement with anomalous scattering (SIRAS) phase calculation utilized the PHASES suite [48] as previously described [19].…”

“…TD was prepared as described previously [13,15] and crystallization, diffraction at pH 7.2 and data processing were as described in [19]. Single isomorphous replacement with anomalous scattering (SIRAS) phase calculation utilized the PHASES suite [48] as previously described [19]. Solvent-leveled [49] SIRAS maps revealed the domain structure and enabled tracing of the chain in the N-terminal catalytic domain (residues 1-320).…”

“…The body-centered crystal is formed by interactions between identically oriented tetramers, where each tetramer contacts all eight of its neighbors at (x ± ½, y ± ½, z ± ½). Crystal growth and morphology have been described [19].…”

“…A fundamental goal of research on allosteric proteins is to correlate the large changes in the activity of these enzymes with changes in their structures [17,18]. TD has been crystallized under several conditions, and three forms have been characterized by X-ray diffraction [19]. In this report, a 2.8 Å resolution structure of TD is described for an unligated crystal form with a single chain in the asymmetric unit.…”

Macromolecular crystallography and structural biology databases a NIST

“…The macromolecular crystallography efforts at CARB furthered the efforts started earlier at NIST in determining the structures of recombinant human interleukin-1β [ 5 , 33 ] and recombinant bovine chymosin [ 4 , 34 – 36 ]. In addition, new programs in protein engineering [ 37 ] of subtilisin BPN’ [ 3 , 38 – 50 ] and hemoglobin [ 7 , 51 – 56 ] were carried out as well as detailed structural investigations of a number of enzymes that included ribonuclease [ 57 – 64 ], several glutathione S-transferases [ 6 , 65 – 82 ], uracil DNA glycosylase [ 8 , 83 – 84 ], threonine deaminase [ 85 – 86 ], and nucleoside diphosphosphate transferase [ 87 – 88 ]. Several other structural investigations were also undertaken and completed [ 89 – 92 ].…”