Dear All, I have been struggling for while with a Molecular replacement problem for a large complex(3 proteins) with 2 copies per ASU. I have a small but 100% model for one of the components but this contributes only 12% of ASU (2 molecules) a much poorer <20% model that contributes the majority 80% of the ASU Space group is P222>P212121 best MR is in P21221. I have strong tNCS as seen in native patterson and phaser chooses this top peak in MR runs: There was 1 non-origin distinct peak (i.e. over 20% of origin peak and more than 15 angstroms from the origin) Sorted by Height ---------------- Height Distance Vector 56.0% 126.4 : FRAC +0.5000 +0.5000 +0.3500 (ORTH 63.0 88.0 65.4) Molrep also uses the same tNCS vector: --- Check Patterson for pseudo-translation --- PST_limit : 0.125 of origin peak INFO: pseudo-translation was detected. Origin Patterson peak: P,P/sig : 26479.002 239.412 1 Patterson peak : p,P/sig : 13591.399 122.888 2 Patterson peak : P,P/sig : 2506.590 22.664 3 Patterson peak : P,P/sig : 1517.345 13.719 Peak 1: trans.vector /ort/ : 62.995 88.023 65.691 trans.vector /frac/: 0.500 0.500 0.352 Peak 2: trans.vector /ort/ : 0.000 0.000 55.510 trans.vector /frac/: 0.000 0.000 0.297 Peak 3: trans.vector /ort/ : 58.238 88.023 65.730 trans.vector /frac/: 0.462 0.500 0.352 INFO: translation vector of peak 1 will be used. My question is how does this affect my MR with the smaller component? Is it exactly the same vector as the larger component? Thanks Trevor