Expression, purification, crystallization and preliminary X-ray studies of the TAN1 orthologue from Methanothermobacter thermautotrophicus

MTH909 is the Methanothermobacter thermautotrophicus orthologue of Saccharomyces cerevisiae TAN1, which is required for N⁴-acetylcytidine formation in tRNA. The protein consists of an N-terminal near-ferredoxin-like domain and a C-terminal THUMP domain. Unlike most other proteins containing the THUMP domain, TAN1 lacks any catalytic domains and has been proposed to form a complex with a catalytic protein that is capable of making base modifications. MTH909 has been cloned, overexpressed and purified. The molecule exists as a monomer in solution. X-ray data were collected to 2.85 Å resolution from a native crystal belonging to space group P6₁22 (or P6₅22), with unit-cell parameters a = 69.9, c = 408.5 Å.