## Algorithm Overview

TTEC is the first published software to predict terminator efficiency. It takes DNA sequences as input and returns the terminator efficiency value.

To calculate the efficiency of terminator efficiency, there are three steps.

1. Use RNA folding algorithm to predict the secondary structure of terminator and and recognize A tail, stemloop and T tail.

2. From the secondary structure, we calculate the free energy of stem loop, and generate a score by considering stem loop free energy and T tail

3. From the score, we predict the terminator efficiency based on the score-terminator equation.

**About Scoring Systems**

Three scoring systems mentioned above were all created by researchers to predict rho-independent transcription terminators. If the score of a sequence is good, it is more likely to be a terminator sequence. The score of terminator consists of two parts, corresponding to stemloop and T tail. Here we made a table to show the similarity and difference of these three scoring systems.

From the table we can see that Elena A Lesnik Scoring System is totally energy based. To calculate free energy we need many thermal parameters. Carleton L Kingsford Scoring System is simple and convenient to use because it doesn’t need to use such many thermal parameters. Thus we use it to help us cut the terminator into three parts.

To know more about the scoring systems, please click each secondary menu on the right.