A clan is defined by the property common to its members. The abbrev iation should reflect this property. The characteristics of all MT families and related subdivision are described in the following text. These characteristics are the criteria used for the classification of the MT sequences. A new sequence should match a majority of the criteria to be included into a family, a subfamily and eventually a subgroup.
All sequences are very similar.
Only protein sequences are known. They display no reasonable similarity with each other and with any other protein sequences. Each of these families includes each only one sequence from yeast which cannot be aligned clearly with each other and with other protein sequences.