Erudite king currently fit to put up shelf (13)
I believe the answer is:
knowledgeable
'erudite' is the definition.
(I've seen this before)
'king currently fit to put up shelf' is the wordplay.
I cannot really see how this works, but
'king' could be 'k' (abbreviation for king in chess) and 'k' is present in the answer.
'currently' could be 'now' (I've seen this in another clue) and 'now' is found within the answer.
'fit' could be 'able' (similar in meaning) and 'able' is found in the answer.
'shelf' could be 'ledge' (synonyms) and 'ledge' is located in the answer.
No letters remain.
This explanation may well be incorrect...
(Other definitions for knowledgeable that I've seen before include "Intelligent and well-informed" , "Erudite" , "Conversant" , "Well informed" , "Savvy" .)