combine subversion and git on same project

Hi,

I am french developer and just get my phpstorm licence.
My Project is a git clone from a share git project but i have a subdirectory which need to be synchronize with another share project which comes from a SVN (readonly) repository.
So i need to get SVN updates all days and commit/push them through Git.

I was working like this on Eclipse but with Phpstorm it seems that i can't do that, big problem...

Do you know any issue to combine these two VCS on one project ?

Actually, if i do git commit, an error appears :
Error: svn: E170001: Commit failed (details follow):
svn: E170001: MKACTIVITY of'/!svn/act/38......[sequence number]......': 403 Forbidden (http://[url svn repository])

I don't know what the mean of that :
- my commit go through SVN ?
- SVN block GIT activity ?

Thank you for your help. Any issue/adaptation welcome !

Best regards.
(i am sorry for my bad english speaking)