Could gates serve as such a door? (5)

I believe the answer is:

stage

I'm a little stuck... Click here to teach me more about this clue!

'a door?' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?

'could gates serve as' is the wordplay.
'gates' anagrams to 'STAGE'.
However, I am not sure how the anagram is indicated.

'such' is the link.

Can you help me to learn more?

(Other definitions for stage that I've seen before include "Acting platform; coach" , "horse-drawn vehicle" , "division" , "Put on (a performance)" , "Theatre platform; leg" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.