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A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z SSETI@home: A distributed computing project named the Search for Extraterrestrial Intelligence at home. SETI@home uses the Arecibo Telescope to record signals and analyze them via the 2 million users running the SETI@home client. Similarity The extent to which nucleotide or protein sequences are related. The extent of similarity between two sequences can be based on percent sequence identity and/or conservation. In BLAST similarity refers to a positive matrix score. Solute is the substance dissolved in a solvent in forming a solution. Solution is a homegenous mixture of a liquid with a gas or solid. Solvation is the interaction of ions of a solute with the molecules of solvent. Solvent is a liquid (commonly) that dissolves another substance or substances to form a solution. spontaneous mutation: In nature, when a species encounters a mutation that keeps spreading until the original species becomes a new species, and the old species is extinct. Substitution The presence of a non-identical amino acid at a given position in an alignment. If the aligned residues have similar physico-chemical properties the substitution is said to be "conservative". Substitution Matrix A substitution
matrix containing values proportional to the probability that
amino acid i mutates into amino acid j for all pairs of amino
acids. such matrices are constructed by assembling a large and
diverse sample of verified pairwise alignments of amino acids.
If the sample is large enough to be statistically significant,
the resulting matrices should reflect the true probabilities of
mutations occuring through a period of evolution. BLOSUM62 Substitution Scoring Matrix. The BLOSUM 62 matrix shown here is a 20 x 20 matrix of which a section is shown here in which every possible identity and substitution is assigned a score based on the observed frequencies of such occurences in alignments of related proteins. Identities are assigned the most positive scores. Frequently observed substitutions also receive positive scores and seldom observed substitutions are given negative scores. Superfamilies consist of proteins that have similar folding motifs but do not exhibit sequence similarity. Author: Tug Sezen |
