Deputy to close bank (6)
I believe the answer is:
depend
'bank' is the definition.
(I've seen this before)
'deputy to close' is the wordplay.
'deputy' becomes 'dep'.
'to close' becomes 'end' (I've seen this before).
'dep'+'end'='DEPEND'
(Other definitions for depend that I've seen before include "Hang down or be connected to something" , "Dangle - rely" , "Count on or hang from" , "Put trust (in)" , "Rely or hang on" .)