Hi Allen, With such low solvent content (and corresponding tight packing), you may want to give 'Queen of spades (Qs)' a try. The reason being that Qs is not (at least directly) a Patterson-based method (and does not assume that intra-molecular vectors are topologically segregated). If you expect that your model is good, do not hesitate to give it a try with even 2A data (but also try 3A ;-). If you have access to a dual- or quad-core machine, do compile the MPI version (see http://norma.mbg.duth.gr/index.php?id=about:benchmarks:qsmpi for results on relatively recent hardware).
My twocents, Nicholas On Fri, 19 Jun 2009, Sickmier, Allen wrote: > I am trying to do molecular replacement on a small peptide (less than 40 > AA) and have not had any success using phaser. Are there any tricks or > better programs for really small peptides? The data is great 1.1 A, ~35% > solvent, and two molecules in the ASU. I have tried all the standard > stuff, changing resolution cut off etc. I may move to sulfur phasing at > this resolution but I would like to get the MR to work. > > > Allen -- Dr Nicholas M. Glykos, Department of Molecular Biology and Genetics, Democritus University of Thrace, University Campus, Dragana, 68100 Alexandroupolis, Greece, Tel/Fax (office) +302551030620, Ext.77620, Tel (lab) +302551030615, http://utopia.duth.gr/~glykos/