extractseq: 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/extractseq - from package: emboss

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

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