Constants | Periodic Table Part A A schematic structure of the subunit of hemery
ID: 574424 • Letter: C
Question
Constants | Periodic Table Part A A schematic structure of the subunit of hemerythrin an oxygen-binding protein from invertebrate animals) is shown below It has been found that in some of the -helical regions of hemerythrin, about every third or fourth amino acid residue is a hydrophobic one. Suggest a structural reason for this finding This order of residues stabilize turns and affects the angle of rotation of spiral turns. O The four helices could be arranged so that to stabilize hydrophobic core The hydrophobic residues share polar regions of the helix, forming a regular helical structure Submit Request Answer Part B What would be the effect of a mutation that placed a proline residue at point A in the structure? This would break the helix near the Fe2 binding sites, and the mutant protein would change functions This would break the helix near the binding sites and Fe2 could not be bound, and the mutant protein would be nonfunctional This would break the helix and form hairpin structures, that would make the mutant protein nonfunctionalExplanation / Answer
PART A
Option B
The four helices could be arranged so that the hydrophobic side chains would all point toward the center of the bundle and would pack together there. This would give a stabilizing hydrophobic core.
PART B
Option B
A proline at this position would break the helix near the Fe2 binding sites. This would probably mean that Fe2 could not be bound and the mutant protein would be nonfunctional.