He's going around state with writer responsible for journey to the east (5)
I believe the answer is:
hesse
'he's going around state with writer responsible for journey to the east' is the definition.
The definition suggests a singular noun which matches the answer.
'he's going around state with' is the wordplay.
'going around' says the letters should be written in reverse.
'state with' becomes 'ess' (I can't justify this - if you can you should give a lot more credence to this answer).
'ess' in reverse letter order is 'sse'.
'he'+'sse'='HESSE'
Can you help me to learn more?
(Other definitions for hesse that I've seen before include "Hermann --, German author" , "German state, capital Weisbaden" , "poet" , "Hermann --, German writer" , "writer in Germany" .)