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Unformatted text preview: of cytochrome c proteins from Human and Cucumber.
The computer program first aligns the sequences to find the maximum number of matching
amino acids; these are indicated by the vertical bars “|”. It then counts the number of amino
acids which are identical in both cytochrome c’s.
| ||| || ||||| || || |||| ||||| | ||||| |||||
Cucumber: EDTLMEYLENPKKYIPGTKMIFVGIKKKEERADLIAYLKKAT 103
| || || ||||||||||| | | ||
EKTLYDYLLNPKKYIPGTKMVFPGLKKPQDRADLIAYLKEAT 110 This uses the single-letter
amino acid code:
A = alanine
etc. Millions of years since common ancestor. These two species come from different kingdoms (plantae and animalia) and their cytochrome
c’s only have 69 out of 102 amino acids that are identical. That is, 102-69 or 33 substitutions
have occurred since the two organisms last had a common ancestor.
With such a large number of substitutions, it is
possible that a given am...
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