diff --git a/modules/io/doc/mmcif.rst b/modules/io/doc/mmcif.rst
index 855ed0ea208cfd8cd77ef537edd736144f6260ff..e172b34a3a7d393adf230dbd0444ec29a691981b 100644
--- a/modules/io/doc/mmcif.rst
+++ b/modules/io/doc/mmcif.rst
@@ -746,6 +746,7 @@ of the annotation available.
   .. attribute:: align_id
     
     Uniquely identifies every struct_ref_seq item in the mmCIF file.
+
     :type: :class:`str`
 
   .. attribute:: seq_begin