Pub has appeal, commonly, is that not so? (5)
I believe the answer is:
innit
'commonly is that not so?' is the definition.
(informal or common word meaning 'isn't it?')
'pub has appeal' is the wordplay.
'pub' becomes 'inn' (I've seen this before).
'has' means one lot of letters go next to another.
'appeal' becomes 'it'.
'inn'+'it'='INNIT'
(Other definitions for innit that I've seen before include "word of emphasis" , "do you agree?" , "that produces stress for some" , "Common question" , "Mere spoken punctuation" .)