Purification, crystallization, and preliminary X-ray analysis of a putative N-terminal acetyltransferase encoded by a Salmonellainfecting bacteriophage

Bacteriophages infect host bacteria and control host metabolism through diverse mechanisms. We noted a gene harboring homology in the N-terminal acetyltransferase of a bacteriophage SPN3US, which infects Salmonella. The phage-encoded gene is phylogenetically remote from the typical N-terminal acetyltransferases whose structures are available. This study reports a preliminary analysis of the crystals of phage-encoded N-terminal acetyltransferase, including its purification and crystallization. The crystals diffracted X-rays to a 2.2 Å resolution, revealing that the crystals belong to P6122 or P6522 with unit cell parameters of a = 68.5 and c = 219.0 Å. We are now growing the selenomethionine-substituted crystals to obtain the phase information. The protein structure will provide molecular insights on how the phage hijacks the bacterial host metabolism.