The Clustal ALN sequence-alignment format includes characters symbolizing degree of conservation in a column. These can be shown in the Conservation header of an alignment in the Sequence Viewer.
Positions where every residue is the same type (complete identity) are marked with an asterisk (*).
Positions where one of the following strong groups is fully conserved are marked with a colon (:).
Positions where one of the following weak groups is fully conserved are marked with a period (.).STA NEQK NHQK NDEQ QHRK MILV MILF HY FYW
The groups are defined using the PAM250 matrix; scores within the strong groups are > 0.5 and scores within the weak groups are positive but ≤ 0.5.CSA ATV SAG STNK STPA SGND SNDEQK NDEQHK NEQHRK FVLIM HFY
Other positions are not marked with any character.