have no output

[Trista]

hi,
i run `snap --get-hbonds -i=1FFK.pdb -o=1.snap` hoping to figure out interactions between the a.a and RNA.
log reported as below:

Processing file '1FFK.pdb' [1FFK]

Time used: 00:00:00:03

But I cannot get my output,1.snap,why?There is no hbonds within this structure?

[xiangjun]

Hi,

I've tried SNAP on 1ffk and did not find any H-bonds between proteins and RNA, as you reported. However, trying SNAP on 1s72 reports 1749 H-bonds. So I guess it must be due to atomic coordinates issue with 1ffk. You may want to dig into 1ffk deeper to understand why, but I believe SNAP is doing its job as designed.

Hope this help.

Xiang-Jun

Did you know that you could also use DSSR with JSON output to easily parse H-bonds?

Code: [Select]

x3dna-dssr -i=1oct.pdb --json | jq '.hbonds[] | select(.residue_pair == "nt:aa")'
The underlying algorithm for H-bond detection is the same for DSSR and SNAP, with the default text output tailored to nt:nt and nt:aa respectively. With the DSSR --json option, 'ALL' H-bonds are reported. In the near future, the --json will be available to SNAP as well.

[xiangjun]

As a follow-up, I've checked the coordinates file 1ffk.pdb. As shown below, only CA atoms are present for the protein components. That explains why no H-honds are detected by SNAP at the protein-RNA interface.

Code: [Select]

ATOM  60615  CA  GLY A   1      90.042 119.507  70.725  1.00 19.43           C 
ATOM  60616  CA  ARG A   2      91.130 122.831  69.274  1.00 20.79           C 
ATOM  60617  CA  ARG A   3      94.149 123.627  67.107  1.00 20.95           C 
ATOM  60618  CA  ILE A   4      97.217 124.158  69.269  1.00 22.45           C 
ATOM  60619  CA  GLN A   5      99.055 127.467  68.965  1.00 21.75           C 
ATOM  60620  CA  GLY A   6     101.878 126.130  66.843  1.00 20.71           C 
...

Best regards,

Xiang-Jun

[Trista]

Thank you so much!
I will try another rRNA structure!