background: -running on linux 14.04

-using nr database for proteins

-the chain_A from 1B72, that has been separated based the chain identifier

i'm sure I download blast and the database properly since

psiblast -subject chain_A.fasta -in_msa chain_A.fasta -out_ascii_pssm chain_A.pssm

actually returns a txt file, but when I try to do

psiblast -query chain_A.fasta -db nr -out_ascii_pssm chain_A.pssm

the terminal just halts and gives no output, not even errors I don't know what to do at this point