I have a unusual set up with a website. Unfortunately I cannot serve the website source from the root domain i.e.

http://www.example.com

I've been forced to redirect to a subdirectory to display the website content when the root URL is requested e.g.

http://www.example.com

Has a 301 redirect to:

http://www.example.com/subdirectory/index.html

Would it have an adverse affect on SEO to have this at the root domain?