backtranseq: command not found

Have You tried accessing the binary with the full path?

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/backtranseq - from package: emboss

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