Structure determination of the O-methyltransferase NovP using the `free lunch algorithm' as implemented in SHELXE

The crystal structure of NovP, an O-methyltransferase comprising 262 amino acids, was solved by SIRAS using 1.35 Å native data and 2.45 Å data from a single mercury derivative using a combination of partial chain tracing by hand of the initial very noisy map followed by data extrapolation to 1.0 Å resolution.