Commit finished with error

Hi support!
I can't commit any files/folders in my SVN repositories.
I using the server packages:
  - subversion-1.7.14-10.el7.x86_64
  - httpd-2.4.6-45.el7.centos.4.x86_64
  - mod_dav_svn-1.7.14-10.el7.x86_64
on OS: CentOS Linux release 7.3.1611 (Core)
The 'httpd' daemon is running under user "apache".
Current rights in SVN-directory is:
  -rw-r--r--. 1 root root 1257 May 4 16:37 authz
  drwxr-xr-x. 6 root apache 86 May 4 16:17 branches
  drwxr-xr-x. 6 root apache 86 May 4 16:16 site
  drwxr-xr-x. 6 root apache 86 May 4 15:56 trunk
How can I fix it?
Error logs is below.
Thanks.

-- server log --
==> /var/log/httpd/error_log <==
[Fri May 05 11:13:25.688479 2017] [:error] [pid 2254] [client
172.16.1.35:56420] could not begin a transaction [500, #13]
[Fri May 05 11:13:25.688497 2017] [:error] [pid 2254] [client
172.16.1.35:56420] Can't open file '/svn/branches/db/txn-current-lock':
Permission denied [500, #13]
-- client log --
ayarosh_at_KSS-WS-07:~/Downloads/SVN/branches$ svn status testfile
? testfile
ayarosh_at_KSS-WS-07:~/Downloads/SVN/branches$ svn add testfile
A testfile
ayarosh_at_KSS-WS-07:~/Downloads/SVN/branches$ svn commit testfile -m
"first commit"
svn: E000013: Commit failed (details follow):
svn: E000013: could not begin a transaction

-- 
Best regards,
Artur Yarosh
Constructor of the computer systems
Kamia Security Service
Phone: +380674426605
Skype: artur.yarosh