Space group of journalists provides leader (7)
I believe the answer is:
empress
'leader' is the definition.
(type of imperial leader)
'space group of journalists' is the wordplay.
'space' becomes 'em' (in typography, a space as wide as a letter 'm').
'group of journalists' becomes 'press' (newspaper journalists).
'em'+'press'='EMPRESS'
'provides' acts as a link.
(Other definitions for empress that I've seen before include "She rules over many territories" , "Female ruler" , "Female sovereign" , "Catherine the Great, for example" , "Powerful woman" .)