Directions: Look at the following amino-acid sequences from two warm-water species and one cold-water species and identify where changes in the sequence occurred.

Line 1: C. punctipinnis: Temperate (cold-adapted)

Line 2: C. caudalis: Tropical (warm-adapted)

Line 3: C. xanthochira: Tropical (warm-adapted)

151

GFERHRVIGS GTNLDSARFR HIMGEKLHLH PSSCHGWIVG EHDGSSVPVW

GFERHRVIGS GTNLDSARFR HIMGEKLHLH PSSCHGWIVG EHDGSSVPVW

GFERHRVIGS GTNLDSARFR HIMGEKLHLH PSSCHGWIIG EHDGSSVPVW

201

SGVNVAGVSL QGLNPQMGTD GDSEKWKEVH KLVVDGAYEV IKLKGYTSWA

SGVNVAGVSL QALNPQMGAE GDSENWKAVH KQVVDGAYEV IKLKGYTSWA

SGVNVAGVSL QGLNPKMGAE GDSENWKEVH KLVVDGAYEV IKLKGYTSWA

251

IGMSVADLVE SIMKNLHKVH PVSTLVQGMH GVKDEVFLSV PCVLGNSGLT

IGMSVADLVE SIMKNLHKVH PVSTLVQGMH GVKDEVFLSV PCVLGNSGLT

IGMSVADLVE SIMKNLHKVH PVSTLVQGMH GVKDEVFLSV PCVLGNSGLT

301

DVIHMTLKPE EEKQLVKSAE TLWGVQKELT

DVIHMTLKPD EEKVLVKSAE TLWGVQKELT

DVIHMTLKPD EEKQLVKSAE TLWGVQKELT

Which amino acids changed between the three species? List four of them below, using the number of the amino acid.

Example: Amino acid 189 changed from valine to isoleucine in a warm adapted species.

1) Amino acid 212 changed from glycine to alanine in a warm water adapted species.

2) Amino acid 228 changed from glutamate to alanine in a warm water adapted species.

3) Amino acid 232 changed from leucine to glutamine in a warm water adapted species.

4) Amino acid 314 changed from glutamine to valine in a warm water adapted species.

2. What were the changes in the chemical properties of the R-groups? Use the amino-acid chart to in the Powerpoint file to answer this question.

Example: Both valine and isoleucine are nonpolar.

1) Both glycine and alanine are nonpolar

2) Glutamate went from being electrically charged to being nonpolar.

3) Leucine went from being nonpolar to having polar side chains.

4) Glutamine went from having polar side chains to being nonpolar.

3. How might the changes that you identified affect the proteins structure?

Example: The change would likely have no effect. Neither valine and isoleucine would promote hydrogen bonding with water, because their R groups are nonpolar and thus hydrophobic.

1) There would be no effect since both of their R-groups are nonpolar, so neither would promote bonding with water.

2) The change to alanine would no longer allow for ionic bonding with water and will become hydrophobic and unable to hydrogen bond with water.

3) The change would allow for hydrogen bonding with water and will therefore become hydrophilic and able to properly bond with water.

4) The change would cause the loss of the polar side chain that promoted hydrogen bonding with water and will become hydrophobic and unable to hydrogen bond with water.

4. Assuming that the mutations are adaptive, how should the changes that you identified affect the stability of the protein at low and high temperatures?

Need #4 answered the most. I do not understand how these changes would effect the fish at higher or lower temperatures.