#Pyth, 23 bytes
sm@s+rG1U6i}RrG1_d2c3pz
This might be the first time I've used the p
rint instruction in golfing.
Explanation
z input string
p print it without newline
c3 split into 3 parts
m d for each part:
_ reverse
}R map characters to being in
rG1 uppercase alphabet
i 2 parse list of bools as binary
@ get correct item of
s+rG1U6 uppercase alphabet + nums 0-5
s concatenate and print