Dear Dr. Read,
For the first time, Phaser gave the following warning.XXXXXXXWarning: Input/Default tNCS NMOL (2) does not match suggested NMOL (4): Please check cell content analysis and tNCS to confirm NMOL
Warning: tNCS is present but correction factors NOT applied
XXXXXXX
Hence, I set NMOL=4 (under other setting using the Phenix GUI of Phaser) following which, only the second Warning message was displayed. The LLG and TFZ scores remained the same in both the cases. The warnings remain the same when I try to place more protomers in the ASU.
XXXXXXX Warning: tNCS is present but correction factors NOT appliedXXXXXXX
However, I found the following message from the log file:XXXXXXXXLarge non-origin Patterson peaks indicate that multiple tNCS vectors are present Please analyse peaks for NMOL multiplicity tNCS correction will NOT be applied To activate tNCS correction, enter tNCS vector manuallyXXXXXXXX
I (think, I have) identified the t-vector (0.500 0.000 0.000) but, don't know what parameters of Phaser to tweak with. Any suggestions or pointers to related papers could be very helpful.
I have a similar problem with another dataset of a different protein which is nearly cylindrical.
Thank,Kaushik
On Saturday, 26 November 2016 11:46 PM, Randy Read <[log in to unmask]> wrote:
Hi,
That message should mean that you didn't ask for a number of molecules divisible by the order of the tNCS. With that vector you need to search for an even number of copies.
Let me know if that doesn't explain what you're saying.
Best wishes,Randy Read
----
Randy J. Read
On 25 Nov 2016, at 21:27, KAUSHIK H.S. <[log in to unmask]> wrote:
Hello,
I have a crystal in C2 spacegroup (94.2073 148.003 72.9967 90 97.6686 90) and Xtriage predicts 923 residues in ASU. My protein could be anywhere between 95 to 110 residues long (assuming the terminals could be cleaved). Using a homolog, Phaser gives me a solution with LLG=1072 and TFZ=45. Molrep placed 4 protomers in the ASU however, the crystal packing is poor.
I understand from Phaser that the tNCS is not accounted for (because the structure is linear?). Is there a way the exact location of the tNCS related protomers be predicted using information from SfCheck and Xtriage?
Xtriage information:Fraqc. coord. : 0.500 0.000 0.000Distance to origin: 47.104Height relative to origin: 79.688%p_value(height) : 5.283e-07
SFCHECK:
Pseudo-translation is detected: 62.6%Pseudo-translation vector: 0.500 0.000 0.000
Sorry if my question is too naive.
Thanks in advance,Kaushik Hatti,Molecular Biophysics Unit,Indian Institute of Science,India.
