Pavel Afonine wrote:

Hi Ed,

it looks like occupancies and B-factors need to be refined and refined until convergence. Also, if you apply any distance restraints for clusters (restrain Fe-S distances) make sure these restraints are correct. I've seen many cases like this and typically refining occupancy/b-factors and making sure restraints are correct solves the problem. I've never seen fixing specific parameters help and I can't understand logic for doing this.

OK. I'm not giving any restraints for the cluster, it must be in the monomers library. I can get SF4.cif from CCP4 and set the weights for bonds/angles very low to let the density rule. But now I see the problem wasn't there a few rounds back, and the difference seems to be that I was using 3 macro_cyles instead of 1. Now I repeat exactly the same refinement both ways, seems to be it. So maybe an artifact of not refining to convergence. Odd though, because it was OK in the starting model, and I'm not asking for the B's to be reset initially to 20 or something. Problem seems to be solved by using the default 3 cycles, but in case anyone is interested, B-factors for Fe are pretty much unchanged after refining 3 cycles B-factors for the Fe's but not the S's, decrease by about 5.0 on refining 1 cycle. Overall and protein B-ave increase on refining 1 cycle Looking at the step by step changes, the first cycle out of 3 is not like the single cycle. This is dev-1420 version of phenix. R-factors refining 3 cycles REMARK R-factors, x-ray target values and norm of gradient of x-ray target REMARK stage r-work r-free xray_target_w xray_target_t REMARK 0 : 0.3205 0.3532 3.857969e+00 3.920754e+00 REMARK 1_bss: 0.2433 0.2823 3.683390e+00 3.779722e+00 REMARK 1_weight: 0.2433 0.2823 3.683390e+00 3.779722e+00 REMARK 1_xyzrec: 0.2457 0.2825 3.689060e+00 3.780966e+00 REMARK 1_adp: 0.2463 0.2823 3.690454e+00 3.780932e+00 REMARK 1_occ: 0.2463 0.2823 3.690455e+00 3.780936e+00 REMARK 2_bss: 0.2463 0.2823 3.690087e+00 3.780536e+00 REMARK 2_weight: 0.2463 0.2823 3.690087e+00 3.780536e+00 REMARK 2_xyzrec: 0.2439 0.2821 3.684528e+00 3.778960e+00 REMARK 2_adp: 0.2434 0.2823 3.683429e+00 3.779315e+00 REMARK 2_occ: 0.2434 0.2823 3.683429e+00 3.779316e+00 REMARK 3_bss: 0.2433 0.2825 3.683615e+00 3.779760e+00 REMARK 3_weight: 0.2433 0.2825 3.683615e+00 3.779760e+00 REMARK 3_xyzrec: 0.2455 0.2825 3.688717e+00 3.780899e+00 REMARK 3_adp: 0.2461 0.2824 3.689934e+00 3.780715e+00 REMARK 3_occ: 0.2461 0.2824 3.689934e+00 3.780714e+00 REMARK end: 0.2457 0.2825 3.689963e+00 3.781089e+00 refining 1 cycle REMARK stage r-work r-free xray_target_w xray_target_t REMARK 0 : 0.3205 0.3532 3.857969e+00 3.920754e+00 REMARK 1_bss: 0.2222 0.2930 3.668217e+00 3.804573e+00 REMARK 1_weight: 0.2222 0.2930 3.668217e+00 3.804573e+00 REMARK 1_xyzrec: 0.2284 0.2941 3.681902e+00 3.808504e+00 REMARK 1_adp: 0.2594 0.3133 3.748285e+00 3.841014e+00 REMARK 1_occ: 0.2594 0.3133 3.748284e+00 3.841012e+00 REMARK end: 0.2692 0.2912 3.759155e+00 3.806820e+00 REMARK ------------------------------------------------------------------------ R B-factors refining 3 cycles REMARK |-----overall-----|---macromolecule----|------solvent-------| REMARK stage b_max b_min b_ave b_max b_min b_ave b_max b_min b_ave REMARK 0 : 90.34 16.23 43.10 90.34 16.23 42.91 80.33 27.29 46.57 REMARK 1_bss: 90.40 16.29 43.15 90.40 16.29 42.97 80.39 27.35 46.63 REMARK 1_weight: 90.40 16.29 43.15 90.40 16.29 42.97 80.39 27.35 46.63 REMARK 1_xyzrec: 90.40 16.29 43.15 90.40 16.29 42.97 80.39 27.35 46.63 REMARK 1_adp: 89.27 16.38 42.96 89.27 16.38 42.79 80.39 26.98 46.24 REMARK 1_occ: 89.27 16.38 42.96 89.27 16.38 42.79 80.39 26.98 46.24 REMARK 2_bss: 89.37 16.47 43.06 89.37 16.47 42.88 80.49 27.08 46.34 REMARK 2_weight: 89.37 16.47 43.06 89.37 16.47 42.88 80.49 27.08 46.34 REMARK 2_xyzrec: 89.37 16.47 43.06 89.37 16.47 42.88 80.49 27.08 46.34 REMARK 2_adp: 89.46 16.19 42.92 89.46 16.19 42.74 80.48 26.86 46.22 REMARK 2_occ: 89.46 16.19 42.92 89.46 16.19 42.74 80.48 26.86 46.22 REMARK 3_bss: 89.63 16.36 43.09 89.63 16.36 42.92 80.66 27.03 46.39 REMARK 3_weight: 89.63 16.36 43.09 89.63 16.36 42.92 80.66 27.03 46.39 REMARK 3_xyzrec: 89.63 16.36 43.09 89.63 16.36 42.92 80.66 27.03 46.39 REMARK 3_adp: 89.22 16.53 42.92 89.22 16.53 42.75 80.45 26.77 46.08 REMARK 3_occ: 89.22 16.53 42.92 89.22 16.53 42.75 80.45 26.77 46.08 REMARK end: 89.22 16.53 42.92 89.22 16.53 42.75 80.45 26.77 46.08 refining 1 cycle: REMARK |-----overall-----|---macromolecule----|------solvent-------| REMARK stage b_max b_min b_ave b_max b_min b_ave b_max b_min b_ave REMARK 0 : 90.34 16.23 43.10 90.34 16.23 42.91 80.33 27.29 46.57 REMARK 1_bss: 90.40 16.29 43.15 90.40 16.29 42.97 80.39 27.35 46.63 REMARK 1_weight: 90.40 16.29 43.15 90.40 16.29 42.97 80.39 27.35 46.63 REMARK 1_xyzrec: 90.40 16.29 43.15 90.40 16.29 42.97 80.39 27.35 46.63 REMARK 1_adp: 85.40 23.38 49.20 85.40 23.38 49.17 81.25 33.88 49.84 REMARK 1_occ: 85.40 23.38 49.20 85.40 23.38 49.17 81.25 33.88 49.84 REMARK end: 85.40 23.38 49.20 85.40 23.38 49.17 81.25 33.88 49.84 REMARK ------------------------------------------------------------------------ R starting model oswego 236% grep SF4 sqr1402e_002.pdb ATOM 8568 FE4 SF4 B1003 15.699 21.265 101.440 1.00 31.53 Fe ATOM 8569 FE1 SF4 B1003 15.302 20.444 104.268 1.00 28.32 Fe ATOM 8570 FE3 SF4 B1003 15.072 18.385 101.975 1.00 30.57 Fe ATOM 8571 FE2 SF4 B1003 17.702 19.420 102.964 1.00 32.57 Fe ATOM 8572 S2 SF4 B1003 14.066 20.264 102.463 1.00 39.50 S ATOM 8573 S3 SF4 B1003 16.963 21.440 103.248 1.00 28.46 S ATOM 8574 S1 SF4 B1003 16.723 19.393 100.994 1.00 31.08 S ATOM 8575 S4 SF4 B1003 16.026 18.425 103.963 1.00 29.56 S refining 3 cycles oswego 235% grep SF4 sqr1402e_006.pdb ATOM 8568 FE4 SF4 B1003 15.708 21.268 101.432 1.00 31.37 Fe ATOM 8569 FE1 SF4 B1003 15.283 20.449 104.291 1.00 28.14 Fe ATOM 8570 FE3 SF4 B1003 15.062 18.373 101.986 1.00 30.15 Fe ATOM 8571 FE2 SF4 B1003 17.720 19.419 102.961 1.00 32.34 Fe ATOM 8572 S2 SF4 B1003 14.080 20.264 102.462 1.00 38.64 S ATOM 8573 S3 SF4 B1003 16.943 21.422 103.257 1.00 28.96 S ATOM 8574 S1 SF4 B1003 16.712 19.383 101.004 1.00 31.27 S ATOM 8575 S4 SF4 B1003 16.036 18.446 103.959 1.00 29.32 S refining 1 cycle oswego 234% grep SF4 sqr1402e_005.pdb ATOM 8568 FE4 SF4 B1003 15.763 21.282 101.383 1.00 26.59 Fe ATOM 8569 FE1 SF4 B1003 15.274 20.434 104.305 1.00 23.38 Fe ATOM 8570 FE3 SF4 B1003 15.026 18.351 102.006 1.00 25.63 Fe ATOM 8571 FE2 SF4 B1003 17.779 19.437 102.902 1.00 27.63 Fe ATOM 8572 S2 SF4 B1003 14.132 20.305 102.437 1.00 34.56 S ATOM 8573 S3 SF4 B1003 16.929 21.408 103.255 1.00 28.42 S ATOM 8574 S1 SF4 B1003 16.681 19.335 101.002 1.00 29.49 S ATOM 8575 S4 SF4 B1003 16.105 18.462 103.923 1.00 28.25 S