Question: Warning when running PSI-BLAST
0
gravatar for Ming
18 months ago by
Ming50
Ming50 wrote:

Hello there,

I am trying to looking for homologous genes using the PSI-BLAST function.

1.) I created a blast database of conserved genes that I had downloaded from uniprot

makeblastdb -in mamA.AA.fasta -input_type fasta -dbtype prot -out mamA_db -parse_seqids

2.) I wanted to query my contigs - assembled from a metagenomics dataset and genes were predicted with the prodigal software - against the database that I have created.

psiblast -query contigs.prodigal.faa -db mamA_db -out mamA.psi.blast -num_iterations 3 -out_pssm mamA.checkpoint -num_threads 10 -comp_based_stats 1 -out_ascii_pssm mamA.pssm

However, it came out with these warning: Warning: [psiblast] lcl|Query_46 NODE_1_length_138104_cov_11.046462_46 # 25949 # 26596 # 1 # ID=1_46;partial=00;start_type=ATG;rbs_motif=None;rbs_spacer=None;gc_cont=0.407: Warning: Frequency ratios for PSSM are all zeros, frequency ratios for BLOSUM62 will be used during traceback in composition based statistics

Am I doing something wrong here? Will appreciate if someone could help.

Thank You.

psi-blast • 372 views
ADD COMMENTlink written 18 months ago by Ming50

Typically warnings are just that - warnings. They can usually be ignored if you know what you're doing. Do you still get results out of your command?

What happens if you run the command without outputting the PSSM?

ADD REPLYlink written 18 months ago by Joe17k
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