JavaScript (Node.js), 9830 bytes
This contains many unprintable characters. Below is the structure of the code without the data strings.
_=>(g=n=>n<127?g(n+1,s=/[\n\rACGU\\`]/.test(c=Buffer([n]))?s:s.split(c).join(`...`[j]+`...`[j++])):s)(1,j=0,s=`...`)