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Protein multiple sequence alignment by hybrid bio-inspired algorithms Vincenzo Cutello, Giuseppe Nicosia*, Mario Pavone and Igor Prizzi Nucleic Acids Research, 2011. D00922025 黃任鋒 R00922102 張庭耀 R00922156 陳子筠 R99922158 蘇宏麒. 1. Outline. Introduction & background IMSA
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Protein multiple sequence alignment by hybrid bio-inspired algorithmsVincenzo Cutello, Giuseppe Nicosia*, Mario Pavone and Igor PrizziNucleic Acids Research, 2011 • D00922025 黃任鋒 • R00922102 張庭耀 • R00922156 陳子筠 • R99922158 蘇宏麒 1
Outline • Introduction & background • IMSA • Cloning and hypermutation operators • Results • Conclusion
Outline • Introduction & background • IMSA • Cloning and hypermutation operators • Results • Conclusion
Immunological Multiple Sequence Alignment(IMSA)R00922102 張庭耀 11
IMSA • Two different strategies to create the initial population • New hypermutation operators • solving protein MSA that insert or remove gaps • Gap columns, which have been matched, are moved to the end of the sequence • The remaining elements(i.e. amino acids) and existing gaps are shifted into the freed space 12
IMSA • Considers antigens (Ags) and B cells • Ag is a given MSA instance, i.e. the protein sequences to align • B cells are a population of alignments that have solved(or approximated) the initial problem 13
Outline • Introduction & background • IMSA • Cloning and hypermutation operators • Results • Conclusion
Cloning and hypermutation operators • Represented by “Static cloning operators” • Clones B cells dup times • P(clo) of Nc = d * dup B cells, d is population size 22
InsGap 24
BlockShuffling operator • Select randomly start point in a sequence • BlockMove • BlockSplitHor • BlockSplitVer 27
STRIP_GAPS 31
Aging operator • Eliminates old B cells in populations P(t), P(gap) and P(block) • The generation number of B cell is τB • New population P(t+1) of d B cells selected best survivors by (μ+λ) - selection 32
Outline • Introduction & background • IMSA • Cloning and hypermutation operators • Results • Conclusion
Classical Benchmark • BAliBASE version 1.0, 2.0 and 3.0 • A benchmark alignment database . • The evaluation of multiple sequence alignment. 36
BAliBASE version 1.0 • 141 reference alignments • 5 reference sets 37
BAliBASE version 1.0, cont. • Reference 1: equi-distant sequences with various levels of conservation • Reference 2: family aligned with a highly divergent “orphan” sequence • Reference 3: subgroups with < 25% residue identity between groups • Reference 4: sequences with N/C-terminal extensions • Reference 5: internal insertion 38
BAliBASE version 2.0 • Include all alignments in version 1.0 • Alignments are verified and corrected 39
BAliBASE version 3.0 • same as version 2.0 • contains 218 alignments 40