Expression, purification, crystallization and preliminary X-ray crystallographic analysis of the hyperthermophilic nucleotidyltransferase TTHA1015 from Thermus thermophilus HB8.

The TTHA1015 gene from Thermus thermophilus HB8 encodes a hyperthermophilic nucleotidyltransferase. TTHA1015 has high homology to proteins belonging to two related families: the nucleotidyltransferase-domain superfamily and the DNA polymerase β-like family. However, no crystal structures of these proteins have been reported. Determination of the crystal structure of TTHA1015 will help in elucidation of its function and will be useful for understanding the relationship between the structure and the function of these homologous proteins. In this study, TTHA1015 was expressed, purified and crystallized. X-ray diffraction data were collected to 1.70 Å resolution. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a=65.5, b=34.7, c=42.4 Å, β=119.1°. There was one molecule per asymmetric unit, giving a Matthews coefficient of 1.86 Å3 Da(-1) and an approximate solvent content of 34%.