Most of the time the only similarity we have access to is sequence similarity.

"The sequence similarity provides a big clue for what this gene is doing."

Proteins with limited sequence similarity were identified in species from plants to mammals.

It has been shown that all the above enzymes share some regions of sequence similarity.

Based on this analysis, there is not a clear correlation between sequence similarity and variability.

The acronym means "family with sequence similarity 43, member A".

However, sequence similarities can be extremely low between proteins that share the same structure.

Classification based on sequence similarity was historically the first to be used.

Recognizing any remaining sequence similarity in such cases may be a very difficult task.

However, others are found that have very little, or even insignificant, sequence similarity with other family members.