22 Genome Informatics 16(1): 22-33 (2005) Improvement in the Accuracy of Multiple Sequence Alignment Program MAFFT Kazutaka Katohl Kei-ichi Kuma1
[email protected] [email protected] Takashi Miyata2" Hiroyuki Toh5
[email protected] [email protected] 1 Bioinformatics Center , Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan 2 Biohistory Research Hall , Takatsuki, Osaka 569-1125, Japan 3 Department of Electrical Engineering and Bioscience , Science and Engineering, Waseda University, Tokyo 169-8555, Japan 4 Department of Biophysics , Graduate School of Science, Kyoto University, Kyoto 606- 8502, Japan 5 Division of Bioinformatics , Research Center for Prevention of Infectious Diseases, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582,Japan Abstract In 2002, we developed and released a rapid multiple sequence alignment program MAFFT that was designed to handle a huge (up to•`5,000 sequences) and long data (,-2,000 as or •`5,000 nt) in a reasonable time on a standard desktop PC. As for the accuracy, however, the previous versions (v.4 and lower) of MAFFT were outperformed by ProbCons and TCoffee v.2, both of which were released in 2004, in several benchmark tests. Here we report a recent extension of MAFFT that aims to improve the accuracy with as little cost of calculation time as possible. The extended version of MAFFT (v.5) has new iterative refinement options, G-INS-i and L-INS-i (collectively denoted as [GL]-INS-iin this report). These options use a new objective function combining the weighted sum-of-pairs (WSP) score and a score similar to COFFEE derived from all pairwise alignments.