blastp: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/blastp - from package: ncbi-blast+

You may install the required package with command apt-get install {package}

Error in other languages:
blastp: bevel nie gevind nie
blastp: comandă negăsită
blastp: comando não encontrado
blastp: commande introuvable
blastp: command not found
blastp: käsku ei ole
blastp: không tìm thấy lệnh
blastp: komanda nerasta
blastp: Kommando nicht gefunden.
blastp: kommandot finns inte
blastp: komut yok
blastp: nie znaleziono polecenia
blastp: níor aimsíodh an t-ordú
blastp: no se encontró la orden
blastp: no s'ha trobat l'ordre
blastp: opdracht niet gevonden
blastp: parancs nem található
blastp: perintah tidak ditemukan
blastp: príkaz nenájdený
blastp: příkaz nenalezen
blastp: команда не найдена
blastp: командата не е открита
blastp: 命令找不到
blastp: コマンドが見つかりません