Backdoor

E|-5--4--------------------------5--4----------------------------------------| 
B|-------2-------2--3--2---------------2---------2--3--2---------------------| 
G|-----------------------4--2--1-------------------------4--2--1-2-----------| 
D|---------------------------------------------------------------------------| 
A|---------------------------------------------------------------------------| 
E|---------------------------------------------------------------------------| 

i think the bass is playing these root notes:
G|---------| 
D|---------| 
A|---4---4-| 
E|-2---5---|