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Needleman and Wunsch Algorithm

One of the most widely applied sequence alignment algorithms is the method of Needleman and Wunsch (1970). When supplied with two protein sequences and a matrix of pair-scores (eg. an identity matrix, or Dayhoff's mutation data matrix) the algorithm identifies the best alignment(s) between the two sequences and a score for the alignment. Whilst this approach may be used with virtually any pair of sequences, extending the method to more than 3 sequences is impractical. This computer package implements a heuristic approach to multiple sequence alignment that has been shown to be effective for many protein families. (See Barton and Sternberg 1987b for a description of the algorithm and assesment of accuracy, See Zvelebil et al, 1987, for an application in secondary structure prediction)