Mine accommodates East Anglia’s first religious painting (5)
I believe the answer is:
pieta
'religious painting' is the definition.
(type of painting showing Mary with Jesus' corpse)
'mine accommodates east anglia's first' is the wordplay.
'mine' becomes 'pit' (down the pit).
'accommodates' means one lot of letters goes inside another.
'east' becomes 'e' (synonyms).
'anglia's first' becomes 'a' (1st letter of 'anglia').
'pit' placed around 'e' is 'piet'.
'piet'+'a'='PIETA'
(Other definitions for pieta that I've seen before include "(In painting etc) representation of the dead Christ" , "Religious work resulting" , "weeping figure" , "Devotional painting" , "Artistic representation of Mary with the body of Christ" .)