Watch the Stormy Turnaround 2 online guitar lesson by Jasper Mortier from 50 Blues Bass Licks You Must Know
There's more variations than you can imagine. Like in one of my all time favorite slowblues songs: Jelly Jelly by James Cotton with the incredible Luther Tucker on guitar. In stead of the V#-V in the end the bass plays a IV. And I also mentioned Bobby Bland's version from 1962: in stead of the II-V#-V he plays V-V#-V.