Unfortunately, GTranslate developer uses ‘administrator’ role to protect its menu item under ‘Settings’ menu. Look at the gtranslate.php file, line #231:

add_options_page(__('GTranslate Options', 'gtranslate'), 'GTranslate', 'administrator', 'gtranslate_options', array('GTranslate', 'options'));

The only way to make possible to add access to this menu item for other roles except ‘administrator’ is to replace ‘administrator’ at this line with ‘manage_options’, or any other user capability suitable for your purpose.